@Sparkles14 ah those are important details to share. It might have been a bit far but you realised and admitted for being wrong. That’s part of self growth. It is not an excuse but the end of the day it sounds like you were just extremely vulnerable since you were drunk so I’d definitely control your alcohol intake in the future. As for your self confidence; professional counselling can help with that as well.
I think for now you just have to accept that it happened and look for what you can do to prevent this from ever happening again, like alcohol intake, you can have a good time without getting drunk. It’s been 2 entire months and your partner said it’s no big deal, so it’s time to move on and focus on yourself and your relationship. Definitely seek out professional help though, it sounds like it could help you in more ways than one.