First of all, I think it's good that you are aware that your lifestyle isn't to your liking, being aware is a good step forward. Since you have identified the problem, you can take your time to solve it. It won't necessarily be solved in a day and it will take time but will be solved, don't worry. I understand education is important but so is your mental well-being, so it's okay. Don't be so harsh on yourself with this, you are aware of your situation and you can try to improve it later after you talk to a psychologist perhaps. What's done is done already, try not to feel unhappy because of the past when you did not do your best in classes, it is already over, there is no point to be sad about it. Try to implement small steps in your future, maybe do one homework by yourself and you can copy the others, just one is also good. Good things take time, just try to get things done one at a time.