This confusion you're experiencing is a result to overthinking, as is depression. You overthink a certain problem, it depresses you. You are sitting limits to yourself, and that's what got you into this stage, I believe. If everybody can dig into their toolkit, then tell me exactly why are you an exception? Is it because you fail every time you try? Is it because you QUIT trying? If you fail, then try again, because a lot of successful people were failing miserably until they got it right. It took Einstein years upon years to perfect the theory of relativity, because of one reason, he wanted to do it. Don't tell me "But hey, this is Einstein!", well, Einstein was a human, so are you. If you didn't try, then the 1000 miles road, begins with a step, be brave enough to take it, because you are brave, but you don't know that because your mind is occupied with whatever negativity you stashed in it. Stash positive thoughts, and you'll get a positive life, simple as that.

Sorry if this was a bit harsh, but call it tough love.