You have your whole life ahead of you. You are ambitious, but we need to get you focusing on the good parts about yourself. Your hobbies, your art, your sport, whatever is important to you.
Please go see a doctor. You sound depressed and an antidepressant can work wonders. I wish you the best of luck. Also a therapist will not fix your issues, but it will help you realize the negative thought patterns in your head and recognize them.
I wish you the best of luck.