You seem to be suffering from a bout of self doubt from your
description......
You ought to take things slowly and start searching your soul.
Learn to appreciate yourself for what you are. Love yourself for
your strengths but also acknowledge your weaknesses. Remind
yourself of the achievements you've scored in your life, however
small.......
Take things easy for the time being. Pamper and rejuvenate
yourself. Go to a gym to work out. When your mind is fresher,
you'll feel more alive and confident! Life is a marathon, not a
sprint. You've got a long way more to go so bide your time. Not
good at something, keep working on it. The more times you fail only
means the closer you are to success. It's your life. Live it on
your own and at your own pace. Don't compare with others at all!
Good luck! 