How come movies/video games decrease the motivation to do buddhist practises?

Young householder,

It can happen in regard of asking and answering of questions for the sake of entertainment too!

Yet the mind, not free from desire after sensuality, from the even greater desire for becoming, gaining a stand, needs, if not inclined toward Jhana, an entertaining, a livelihood.

Good to seek out for a "hobby", kammatthan, something given, causing no harm for others, oneself, and dedicated not toward the low and equal but upwardly, toward the Gems.

Giving not at proper time, toward those without metta, Sila, wrong view, ones sacrifices do not bear much to no fruits, even bind one down: the way of sacrifices by the "commpassionate" fools... for it's difficult to lower ones stand and serve more sublime yet feed ones defilement when gaining the notion "look, I help!"

No Sila, no notions of generosity, no desire to renounce... nothing but wrong conncentration for the sake of compensation, the sake of investment toward stand, toward home, house.

Gained some reputation, an approve, fought another battle, decay... toward another game, question, quest in conquering with improper attention another wind-mill monster under run-a-mill.

One would be much wiser to leave the gamers and players domains and seek for sacrifices far aways from drug addicted, dedicated toward something worthy for gifts, for there is no incease of happiness to be excepted investing in what's dedicated for the world.

Encouragement to avoid pirvat, commercial social medias

No Sila, after sensual pleasures, slander around, no conncentration, no exame, lose in this and next world...

(3) "What are the six channels for dissipating wealth which he does not pursue?

(a) "indulgence in intoxicants which cause infatuation and heedlessness; (b) sauntering in streets at unseemly hours; (c) frequenting theatrical shows; (d) indulgence in gambling which causes heedlessness; (e) association with evil companions; (f) the habit of idleness.

"Free" social medias, fb, google, exchange... incl. their inhabitats, are (e). All duties and advices on good friends for young householder here: The Layperson's Code of Discipline

Care for you duties in your relation and don't follow the fools who believe themselfs being monks while holding on house. The food you gain isn't given in faith but as a trade which asks for compensation. Otherwise you fool yourself double, end up as lossy beggar who still clings to sensuality and coupling in his old... standing behind the walls, feeding on left overs by degenerated social-monks shares... running around and citing texts like a small girl dreaming being princess i wonderworld.

[Note that this is not given for stacks, exchange and other world-binding entertainments or to maintain a mast-pet relation, but to escape from this wheel]

At many times in our lives, the food given us is given in faith. This is certainly true of monks. It is also often true of householders who have yet to earn a living.

AN7.72:11.2: Which is better—to have a strong man force your mouth open with a hot iron spike and shove in a red-hot copper ball, burning, blazing, and glowing, that burns your lips, mouth, tongue, throat, and stomach before coming out below dragging your entrails? Or to enjoy alms-food given in faith by well-to-do aristocrats or brahmins or householders?”

The Buddha's message here is sobering:

AN7.72:14.1: “I declare this to you, mendicants, I announce this to you! It would be better for that unethical man to have a strong man grab him by the head or shoulders and make him sit or lie down on a red-hot iron bed or seat. Why is that? Because that might result in death or deadly pain. But when his body breaks up, after death, it would not cause him to be reborn in a place of loss, a bad place, the underworld, hell. But when such an unethical man enjoys the use of beds and seats given in faith by well-to-do aristocrats or brahmins or householders, that brings him lasting harm and suffering. When his body breaks up, after death, he’s reborn in a place of loss, a bad place, the underworld, hell.

Being mindful of the faith others have in us, we bear what has to be born, turn off the TV, take exams. And if the exams are stressful, meditation can help us let go of anxiety so that we might express our gratitude for that which was given by working or practicing for our own benefit and others.

could it be because those entertainments are one of five hindrances?

What happened to me? How those videos cause me to lost my interest for buddhism? How I lost that resistance?

I suspect something you wrote points to the answer – you wrote that college work stressed you out, and these videos “helped me forget the problems.” People respond to stress in their own way, e.g. overeating, indulging in drugs or sensual pleasure, or zoning out on YouTube videos. They’re all easy distractions that are pleasurable in the short term and an escape from your troubles. As you’ve found, watching videos online can become compulsive – there are always endless more videos to watch, endless suggestions and enticements. It may not cause the same obvious physical downsides caused by overeating or drug use, but there is a definite negative effect as it takes over your time and stunts your motivation for other, healthier endeavors. Internet addiction in general is a very real thing, and perhaps reading a bit about it will give you some insight as to how your mind has been affected by your time online.

How can I get back to that previous state?

Not to get technical, but there’s no such thing as going back to a previous state, nor should you want to. You’re currently learning a challenging but important lesson – distractions will always exist, and now you know that a weak spot for you is internet videos. Guess what? You’re going to get through this, and then you’re going to encounter the next challenge and overcome that one, and so on. And at each step you’re going to become wiser about pitfalls, how to avoid them, and how to climb out of them. I suggest you start by reading (or re-reading) about the five hindrances and their antidotes. Of the five hindrances to progress – sensory desire, ill will, sloth-torpor, restlessness-worry and doubt – you seem to be plagued by a mix of the last three. They each have their specific antidotes, in this case such aspects as rousing energy, having a schedule/routine for meditation, and developing contentment and trust in the process. Underlying all of this are the constants of Buddhism: being mindful of our thoughts and impulses, investigating them to understand them, and detaching from them as you realize they’re not “you” and they’re just as transient as anything.

I believe having a schedule/routine for meditation is critical. As the body and mind get used to it, we just automatically do it and are less likely to skip it in favor of distractions. Keep to the schedule and give yourself time to get in a groove. Don’t beat yourself up if it’s tough at first. I noticed that the election week stress threw me off, and I’m just now getting more focused day by day. Best wishes to you.

Whatever you give frequent attention becomes the inclination of mind.

This is similar to how recitation & memorizing works, as more attention is given the recall becomes easier.

Video games are in the scope of sensuality and it becomes the inclination of mind.

It is based on tendencies that are wrong such the perception of attractiveness in the unattractive. It cultivates wrong path.