What is the minimum I need to do to advance?

Consistency and diligence are key factors in ones practice. Without them, progression cannot be gained.

It is the continuity of practice that yields advancement. It's like rubbing to sticks together to make a fire. If one stops rubbing before the fire has started, then the fire will never start.

Similarly, if one has long periods without practice of meditation, then the advancement will not arise or at least it will arise in lesser degree.

Another thing that will derail ones practice, is wanting to get results or worrying about why one is not advancing on the path. These are hindrances, that slow one down.

When doubt arises, i.e. when one is worrying about why one is not advancing, then that is the 5th hindrance arising. That is an oppertunity to gain insights. One should note the hindrance and work with it. One should not react to it or dwell in it, thereby fueling it and making it stronger. Observe it with mindfulness, in the present moment and gain insights about the 3 marks of existence.

If you establish a regular practice, practice correctly and diligently, then you will advance. If you do not practice regularly, then advancement will not come or it will come slower and in lesser degree.

Sounds like you need motivation. You could begin studying the Buddha's teachings yourself, go read the discourses from the Pali Canon and read up on the practice of meditation.

Its also important to not push oneself to practice more than one is ready for. That will only result in one not wanting to practice at all.

It sounds like a good idea to practice a small amount of time each day. You could try that for a week or two and then gradually increase your sitting time. Start small and then work your way up. Also try to incorporate your practice into daily life, outside of formal meditation. For example you can to try to be mindful, every time you brush your teeth, wash your hands or take a shower. Walking meditation is also a great way to gain continuity of practice.

Personal opinion based on my experience: go for a retreat again, if you can. It has more benefit (as a rule of thumb) to do intense practice than the same amount of time diluted over a bigger timespan. Rather than 1 hour every morning, do 20 minutes every morning and a one 10-day retreat a year. I am a big fan of the Mahasi-style practice, and it was developed primarily for retreats; works in daily activities as well, but the foundation is intense practice.

I don't know what the minimum may be in your case. I can say something about my experience with another tradition (Goenka), which may perhaps be helpful.

I sat a 10-day course 2 years ago. It helped me to settle some fears and problems that I was afraid to think of before. As for more mundane, everyday problems, even though I didn't meditate regularly afterwards, I think in retrospect there was a positive change in my attitude for a few months, but it wasn't very clear to me at that time.

This year I went for a 3-day course, and after the course I saw a very significant positive change (it was related to procrastrination, as in your case). It lasted for a few months, roughly as long as I meditated regularly for 2 hours per day. But the point is that I saw that change already during first few days after the course. During the course it was said that meditation must lead to a visible (even if small) change in one's life. If you don't see any such change, you're doing something wrong.

That's my 2 cents. I don't know how much of it may apply to your tradition.

If your practice isn't constant, that will have a major effect on your progress. If sometimes you don't meditate for over a month, that's probably the reason you have had difficulty.

If the reason you're practice isn't constant is because you can't squeeze in long sessions, then it would be better to break them up into several smaller ones. Even just meditating 15 minutes in the morning and evening is much better than getting an hour done but then giving up.

maybe you have made progress but you didnt know it? One of the ways to measure progress is how fast you let go of things that come into contact with your faculties, whether they are agreeable (like) or disagreeable (dislike), and remain in equanimity. As expressed in this Indriya-Bhavaba Sutta Indriya = Faculty.

Buddha used the speed of letting go things in many other sutta such as, drop of water onto hot pan, sparks flying from a blacksmith's hammer, etc.

in simpler term, you are making excellent progress if you can let go of anger (and other feelings) at blink of an eye.

you might be interested in the Cook Sutta. Pay attention to details of your progress, take note, and make adjustments.

Culadasa has broken down the progress into 9 stages. That might be helpful to you.

It's here: http://dharmatreasure.org/wp-content/uploads/LightOnMeditationHandout.pdf

What do a great pianist, a great martial artist, and a great scientist have in common? They work their butts off to perfect their skills. And these are just mundane skillset, not supra-mundane one. The suttas use a popular simile to express the urgency to practice the Dhamma: one should train as if one's clothes or head is on fire! While the exact amount of time for practice varies for different people, a regular daily sitting meditation and precepts observance is a must-have minimum requirement.

From SN 56.34: "Bhikkhus, if one’s clothes or head were ablaze, what should be done about it?”

“Venerable sir, if one’s clothes or head were ablaze, to extinguish one’s blazing clothes or head one should arouse extraordinary desire, make an extraordinary effort, stir up zeal and enthusiasm, be unremitting, and exercise mindfulness and clear comprehension.”"

A little narrative about people and exercise habits. I think it might be helpful in giving you context for your practice. In the years I've worked as a personal trainer, I've seen the same behaviors exhibited by all of my clients. In fact, I can pretty safely predict who will lose weight, get in shape, and keep it off and who will drop out after five weeks.

Client A comes to see me. He tells me that he wants to look good and put on twenty pounds of muscle. Client A has never worked out. I go over my plan of attack with him. Three days a week, no more than an hour a day. I don't even talk about diet or supplementation. He tells me that he thinks my plan is too easy. He wants to workout seven days a week. He wants to know what he can take to drop weight. During workouts, he gets frustrated because he's not seeing enough progress. After about a month, he burns outs, calls me a terrible trainer, and I never see him again.

Contrast this with Client B. She comes in and tells me that she knows she should be exercising but doesn't know where to start. I go over my simple, introductory protocol. She follows it to a T. Bit by bit, she starts to wonder what other changes she could make. She asks questions. We introduce new exercises. She starts reading about nutrition. Slowly, she starts to develop fitness interests - CrossFit, powerlifting, aesthetics, etc. After a couple of months, she knows her strengths and weaknesses better than I do and addresses them under her own volition. Years down the line, I see her sharing advice with other gym members. She's made fitness a part of her lifestyle.

Buddhism, like fitness, is a gradual path. Going on those retreats is like signing up for a marathon when you've never run a mile in your life. You need to start out small. Just fifteen minutes a day will suffice at first. If you can sincerely commit yourself to that small amount of time, gradually your momentum is going to carry you into longer and longer sits (that's the very definition of karma!). The more you sit, the more evident the rest of the eightfold path is going to become. You are going to see how action effects your sitting and how sitting effects your actions. You will see how mindfulness and concentration are like two hands holding up the same cup. You will learn the skillful application of effort and how to keep yourself from burning out. You will also learn what parts of the path are important for you to focus on. When you do, you are going to start asking some very practically oriented questions of your teacher. After a while, the path will become effortless. You'd no sooner skip a day of mediation as you would skip a day of bathing.

But most importantly - all of these gains will be incremental. You won't even notice that they are happening. One day, however, you are going to look in the mirror and notice a very different person looking back at you.

While heavily focused on by western practitioners - meditation is only one aspect towards the cultivation of the mind. If unsupported by the right morality and faith, your mind will be too troubled and unfocused to concentrate on the object of your meditation. In the case of Anapanasati and Vipassana, your object is your breath - but even as you're practicing under Mahasi Sayadaw's teachings, you probably notice that you start off focusing on your breath and noting phenomenons as they arise, but somewhere down the line you realize you've been swept away by a stream of consciousness. Only after the arising of many thoughts, do you even realize this has happened and you try to steer your concentration back to your main object and start once more with the noting. Before you're swept away again...

Thus even if you are able to sit there for a long period of time with the initial intention of practicing meditation, it is difficult to advance.

The keeping of the 5 precepts is a good place to start. But perhaps by investigating the conditioned reality brought forth by the 5 precepts, you can realize for yourself their effects on morality and their qualities of non doubt, non remorse, and arouse sufficient investigative faith to progress.