I just want to second greenfrog's sound advice. I know it's hard, but you'll be better off if you can just accept this right away. There's nothing you can do now to go back and change it, and accidents can happen no matter how careful we are, so there's no use in getting angry at yourself either. Also, like greenfrog said, it could just be a minor thing that resolves quickly, in which case it definitely isn't worth getting worked up over.

Hang in there and stay strong. Accept what you can't change.