What people think of you does not matter. What really matters is what you think of yourself and what God thinks of you. Don't look down on yourself because a lecturer in school said you are worthless or your boss at work said you are not useful.
Whenever you wake up, say to yourself, 'I'm the best, I'm the reflection of God's image, nothing can stop me'. Get your spirit high. The opinion of others should not determine your reality. Get out of your shell and shine brighter than the sun.