it's fine. We all make mistakes.
"He who has never made a mistake. Has never learnt anything new." -Albert Einstein
Look. Even Albert agrees. Mistakes are a part of life. You shouldn't be scared of them. You should understand them and learn from them :D don't feel like shit. At least now you know what to do next time. If you never made any mistakes... do you really think you would learn? Also seriously it's fine. It happens a lot.