It's okay OP, we all fail, again and again even, your not alone there. I suggest you take the advice someone else gave you attempting to sort out your depression, easier said than done I'm sure but I think if you somehow get to grips with it, even if it's only a little bit, it will have a positive impact on you. I also suggest not giving up! Try your hardest to understand what seems impossible to understand, that sense of achievement will help you accomplish the next task, then the next task and also impacting you and your depression positively. I say you and your depression because it doesn't belong to you, nor are you obliged to carry it around with you letting it effect your life so negatively, seek the help you need and begin to make a change, it will help you greatly and especially on achieving your goals.