Why can't I just prove myself?

Honey don't sweat it. We must all make biiig mistakes while treading on the path of learning responsibility. Some parents are very controlling and overprotective, and while they may be doing so out of care and love, their execution isn't right. Maybe that's how they were raised and they think it's right for you too, but it's not. We all learn differently. So don't take his criticism.
Make the bones in your skeleton your home. I read that somewhere. But it makes sense. No one can tell you what's right or wrong in your mistakes as much as you as the learner can, from the pain of the mistake. Parents know, they might be harsh, but dig out the crux of their lessons, the ones that are positive, even if it's only one in your entire life . Ditch the negatives in the trash. Draw what you like. Sell it if you wish. Make your mistakes. Be disappointed. And learn. Make new mistakes...but forgive yourself for making old ones again. You can be homeless, cold, struggling. But don't ever tell yourself you're weak. Those bones, they're you. Not anyone's opinion of you. Be kind to yourself.

You know, I kinda know how do you feel. My dad always was the type of supportive guy,even if we have our differences. But if he is very openly to make me discover my only path, he's that kind of guy that pusses you to make the things, like entering in college or getting a job. This makes a lot a pressure on me. I used to feel like I needed to impress him, so I always tried to make good things to make him proud. But I lose a bit of myself in that process. I think I trying to say is, don't lose yourself for him. I don't know if that helps you though