It's OK. Really, it is. No one wants to make mistakes, but everyone does. If someone tells you that they don't they are either lying to you or they are just scary because they don't realise their mistakes.
It's a scary feeling-heart in your toes when you realise that happened. Plus, being accountable for mistakes is never fun. It's tough on the ego and you already trying to prove yourself as a new grad.
I can almost guarentee that you are probably just flat paraniod after this, from reading your post, you appear to be super careful. Just keep doing what you are doing and learn from it. Unfortunately, mistakes are how you learn how to prevent it from happening again. You get little methods in place. My first mistake was in orientation. I had been a nurse for only 2-3 weeks! Luckily, no one was hurt. Just learn from it and move on. It's not worth the stress because you can't take it back. You can prevent yourself from making the same mistake again though. If you were my nurse, I'd request you the next day because I bet you will be one of the safest on the floor from obsessively double checking everything.