More importantly you have to dig deep down and ask yourself who is it that you want to be. No not what your parents friends and teachers want you to be, but you. I am talking about figuring out what makes you happy, no matter how crazy it sounds to the people. If it makes you happy then go after it with all of your heart.
Trusting yourself can be difficult at times due to that little voice inside of your mind that's always pulling and tugging your brain into different directions. Matters can seem even more complicated when you're not happy with yourself or your current situation. Also when the people around you tell you that you can't do something that adds more weight on your heavy shoulders.
Ignore all of those voices and focus on what makes YOU HAPPY!
Happiness is one thing that we all seek for and look to obtain by getting money, getting married, going to school, or acquiring other things outside of ourselves. These things are outside of you, and true happiness comes from within. You have to trust yourself and find out what makes you happy inside. If eating a bologna sandwich makes you happy then do it. If making people laugh makes you happy then do it. If drawing and creating paintings makes you happy then do it your very best.
A large percentage of people are stuck in dead end jobs, and trapped in situations because they never take time to figure out what they want to be. Or perhaps they have discovered what they wanted to be, but somewhere along the road they let other people talk them out of it. This isn't you trusting yourself. It's you being weak and insecure...
You won't get anywhere in life if you don't trust yourself. You are the only YOU that you have, and at the end of the day you are the only one laying your head down on the pillow. My friend trust yourself, and do what makes you happy. If it doesn't make you happy, then don't do it.
Happiness is the key, trust yourself and do what makes you happy!