I'm not a big fan of trite aphorisms. Today may be the first day of the rest of my life, but putting it that way doesn't really do much for me. But today in a presentation about teaching and learning I saw the phrase "Failure is not a state, it is an event". I didn't get time to jot down the attribution, and the best that the internets can come up with on the matter is this, but I do think that this is a crucial thing to remember.
Never think of yourself as a failure if something you try doesn't work. Just think of yourself as someone who has now got some valuable knowledge along the lines of: "I need to do that differently".
I think you learn more from your failures than your successes. And fear of failure is worse than failure itself. I now allow myself the luxury of trying things that might fail on the grounds that worst case I'll know more than I would by doing nothing. And it is always possible I might succeed.