The very first thing to understand about “proving yourself”, is that YOU need to be the first person you convince. You need to develop your abilities hand-in-hand with your confidence to the point where you feel pride in what you can do. Once you reach that point, you can then work on impressing other people.

I cannot stress enough what I am about to say: have a hobby. Find something you enjoy doing for its own sake, something separate from your primary artistic pursuit.