Well, I really can only give advice for the school work because that is literally all my life is right now.

Take a deep breath. Think about the long run. Will this one assignment even count thirty years from now? Don't let school work consume your life. You need self help time. Set apart time in the day when you can just sit and meditate and think about life. Repeat postive mantras (again, positive) to yourself. I know that you feel like you aren't good enough but you are.