let go of wanting to change the past in my meditation practice

Metta practis, (starting ones session, after Venerations, with metta spreading, but also much of it best all the time) is the usual counterpart to overcome ill-will, good householder.

What ever meditation, trained without right view present, without gratitude, without metta, if even gaining concentration, would lead just to wrong concentration. So actually better to do not develope a wrong path. Right effort turns around right view, right resolve and virtue.

Ill-will toward ones parents, lack of gratitude, is a very grave sign of wrong view, young householder. No change to ever progress if ones beneficer aren't placed right in ones heart.

[note that this isn't given for stacks, exchange, or other world-binding trades, but for an escape from this wheel]

Aren’t the main questions there first what you remember your teacher expounding and then what your teacher said when you raised this very Question?

I don’t need to be a Buddhist to know there are broadly two types of meditation: transcendental and others.

Broadly, the “transcendental” part of TM is literal: the method moves above and beyond any idea of letting go, or wanting, change or past even while it’s letting go.

Broadly, other methods - possibly including Buddhist - concentrate on a subject for what can be learned from it. Concentrating on the breathing puts your teaching in the second group, though closer to TM than most.

Who doubts that if in meditation you are clinging to wanting to change the past, that’s broadly for two reasons.

The first would be that in the context of meditating, all the details in your Post were simply details with no bearing on the idea of the past, or of changing it, or of clinging.

Further, if you must mediate on a subject don’t you think that subject should be not the past, nor wanting to change it, but the concept of clinging?

Personally, I don’t think this Question belongs to Buddhism, unless someone’s suggesting Buddhism is most about meditation.

I think that memories have to be explored and expressed warmly and strongly and emotionally and loudly when they are agitating you, and that you should not sit still, so find some forest or put on some music or find a friend or a worker who is good to talk to about these things, and express yourself. I have similar memories and they take time to abate, and expressing them without the constraints of society will give your mind some peace. Over time the memories will become less fresh in your head and your will fill your life with nicer memories which will replace them, and you will find that memories are like a sting or a cut or a depression, it's good to express feelings and also find better memories and goals and dreams to motivate you.

Having a good talk with a friend or a good shout about something when you are chopping some wood or shaking some trees or is the natural way to feel better, and it gives a good feeling after, and you need to do it as many times as you need to until your memories have an emotional outlet. Perhaps it takes 10/20 years, but it's better to express memories.

Buddha came from a very happy and serene and peaceful home. He only witnessed worldly hardships when he traveled away from his parents and his home. This gave him an advantage for studying spirituality, temptations, meditation, but Buddha's teachings are less developed than some of today's psychology for expressing traumatizing memories, because Buddha didn't allegedly have very many of them.

This means that you have a strong emotional barrier in your mind. Meditation is very good for mental focus and inner peace, although you can try modern methods of dealing with complex repressed memories which are trying to be externalized.

I'd recommend talking to a psychologist or an energy worker or a good friend or a tree or some rocks and telling them how you feel, so that you get the words out that you want to say. I expect that you want to express yourself on the subject and that has been suppressed, so it is trying to rise up. Scientology is generally corrupted, although there is a positive notion of going into early memories with a positive memory worker and finding what your memories mean to you.

I hope this finds you well today.

Lots of good advice here addressing the roots, causes, conflicts, and how the sacred texts apply. But if you’ll indulge me, I’d like to step back and look at it terms of practice.

Think of it like, you’re getting a lot of good advice from doctors, and I’m just your buddy at the mental gymnasium.

There’s a Catch-22 will recurring thoughts. On one hand, they are disrupting your practice. On the other, the thoughts are not good or bad. They just are, and fully experiencing them is part of the way.

My Secular Buddhism 101 way to approach them, focusing on practice and not doctrine or dogma, is through the practice of noting. I don’t wanna put words in your mouth, so speaking generically, maybe categorize it as regret or reminiscing or obsessing about the past. Noting, then, is the first step in the process described by the three most powerful words in the universe: simply begin again. You note the thought, feeling, or sensation, and then remind yourself to simply begin again.

A good refresher is here: https://mindfulnessexercises.com/noting-thoughts-to-see-where-the-mind-is/

Another good reference is the seven part Basics I course by Joseph Goldstein over at tenpercent.com For my money, no one covers noting better than Joseph, and his writings, lectures, podcasts and what not are pretty easy to find.

I also wanna throw one more thing out there, that works for some people, others not so much, but definitely worth a try. I first heard it from the writer and teacher Jeff Warren, https://jeffwarren.org/exploration/welcome-to-the-party/

Jeff’s technique is to take noting, apply some humor (which sounds counterintuitive for dealing with anything serious or traumatic), and welcome the thoughts to your session. For me, it is typically regret for past actions that I have not fully put aside. “Hello, regret, welcome to the party. Together, let’s simply begin again.”

One more pop culture quote that I think summarizes it. From Andy Prudhomme: The part of your mind that is thinking will try to tell you that more thinking is the answer. This is no different than any other social interaction. If you are a farmer, and your crop is struggling, the guy who sells seeds will tell you you need to buy better seeds. The guy who sells fertilizer will tell you that you need better fertilizer. And the guy who sells tractors will tell you that you need a new John Deere. Our mind does the same thing to us, and the thinking part of our mind tells us that we need to obsess and analyze and contemplate everything in our past. So, from a “training the mind“ standpoint, we are acknowledging the thinking part of our mind, asking it to walk with us, and simply beginning again.

Just wanted to look at it from a “how” instead of a “what” or “why” standpoint. I hope there’s something useful for you in here.

Be well and stay safe!

Case 2 of the Mumonkan The Wild Fox

Every time Baizhang, Zen Master Dahui, gave a dharma talk, a certain old man would come to listen. He usually left after the talk, but one day he remained. Baizhang asked, “Who is there?”

The man said, “I am not actually a human being. I lived and taught on this mountain at the time of Kashyapa Buddha. One day a student asked me, ‘Does a person who practices with great devotion still fall into cause and effect?’ I said to him, ‘No, such a person doesn’t.’ Because I said this I was reborn as a wild fox for five hundred lifetimes. Reverend master, please say a turning word for me and free me from this wild fox body.” Then he asked Baizhang, “Does a person who practices with great devotion still fall into cause and effect?”

Baizhang said, “Don’t ignore cause and effect.”

Immediately the man had great realization. Bowing, he said, “I am now liberated from the body of a wild fox. I will stay in the mountain behind the monastery. Master, could you perform the usual services for a deceased monk for me?”

Baizhang asked the head of the monks’ hall to inform the assembly that funeral services for a monk would be held after the midday meal. The monks asked one another, “What’s going on? Everyone is well; there is no one sick in the Nirvana Hall.” After their meal, Baizhang led the assembly to a large rock behind the monastery and showed them a dead fox at the rock’s base. Following the customary procedure, they cremated the body.

That evening during his lecture in the dharma hall Baizhang talked about what had happened that day. Huangbo asked him, “A teacher of old gave a wrong answer and became a wild fox for five hundred lifetimes. What if he hadn’t given a wrong answer?”

Baizhang said, “Come closer and I will tell you.” Huangbo went closer and slapped Baizhang’s face. Laughing, Baizhang clapped his hands and said, “I thought it was only barbarians who had unusual beards. But you too have an unusual beard!”

I think you're looking at this backwards. There is ultimately nothing that anyone can say that will help you. Your past is your past. How it impacts you in your present life is up to you to disentangle. All of those feelings of regret, of wanting something to be other than it was, all of that is uniquely yours for 500 lifetimes unless you can find the key to liberation. Fortunately, the fact that you're sitting puts you half way there already.

But what kind of sitting are you doing? When we first start down the path of meditation, we can quickly become enraptured by the states it offers. It can almost feel like those sits that aren't peaceful, tranquil, and transcendent are missed opportunities. All of the distractions that we endure, all of those petty unresolved aspects of our personal history - we get agitated because they disrupt that bliss. How can we become Buddhas if our pasts keep pulling us out of samadhi???

So many people stupidly ride an ox the foot of the hill when really they should be dancing with foxes in the mountains.

We all have our foxes and each one is a terrific opportunity to wake up. Clinging to what could have been has a red face and a bushy tail. Keep sitting and looking at that clinging. Make friends with it. Get to know what it likes, who its friends are, and what it eats for dinner. Sit with it. Nourish it with your practice. Feed it with emptiness. Dance with it under the moon. And when it finally dies, I promise you that you'll want to give it a monk's funeral.

The scripture Iti 74 says a child who practises Dhamma is superior to parents who do not practise Dhamma.

You cannot change the past.

However, you can clearly comprehend the immoral & wrong actions of your parents and then aspire to live in the opposite way.

You can aspire to not be like them, which means you treat other people in the manner you yourself wished you were treated.

In other words, you aspire to never ever repeat your parents mistakes & errors.

If you have some care for your parents, you can dedicate your efforts to your parents, as though to make merit for their sins.

As for 'gratitude to parents', the scriptures say children honor & venerate their parents who have been compassionate (rather than cruel) towards them. Refer to Iti 106.

Also, refer to my answer to this related question.