[mcv]

My thought exactly. Depression is a serious illness that can kill.

It is hard to give advice on the OP's professional situation (do you underestimate your ability? do you need a better way to learn? should you be looking at different talents and try a different career? no idea), but the way OP responds to his situation is very concerning.

If you do suffer from depression or some other psychological condition, it's entirely possible that that's the very thing that's holding you back. Talk to some experts, and deal with that. It might solve a lot of your problems.