There are some things you have to accept, before you can move on...

I wish I could compile a guide for aspiring artists, tell them everything they need to know before they have to deal with it.  Of course that would ruin the surprise.  And I wouldn't be able to enjoy them squirm in their agony. 

There are some things you have to learn to accept, and failure is one of them.  Sometimes an idea doesn't pan out.  Sometimes no matter how hard you try, it never will.  Failure is part of the process of learning.  It helps you avoid certain things, ideas, habits even.  Failure will help you understand and theorise better ways of approaching your ideas--reworking them, questioning what could be done better.

Failure is not the same as never trying (go to class, do your goddamn work!).  Failure is trying, experimenting, but finding an unsatisfactory result.  But be satisfied that you can accept failure; accept it, do not dwell on it, move on.