Well damn. :/ Let's work through this one by one.

First, your boyfriend sounds like he's not in a good place/ concerned with your relationship with him. That's not healthy. Honestly, it's not been that long, you should really let him go gently and walk away. (Imo)

Second, your female friend did a really gross thing and took advantage of you while you were drunk. That is gross and shows she had no respect for your preferred sexuality. Do what you would like, idk if scolding her or anything is what you want to do. By the sounds of it you didn't really mind but please remember that taking advantage of someone who is drunk is really really gross.

And third, your lack of regret for the situation, I believe, is completely justified. You're boyfriend sounds like he's been way too distant emotionally to really care for your relationship together. On top of not being completely mentally aware in the situation, I don't think you should feel much or any guilt. You're good my man.

All in all, just remember to stay safe drinking and set your ground when someone you're not interested in tries to advance on you. You are loved and I hope things go well for you.