Hey guys, I'll cut right to the chase -

Over this past weekend I was a part of a big joint birthday party with a bunch of friends. The itinerary included lots of drinking and eventually moving the party to a bar. Like an idiot I drank far too much on an empty stomach and ended up blacking out by the time the group made it to the bar. This is where things went very south. Apparently while I was there I grabbed my girlfriend by the neck while she was talking to some other people and pulled her over so that she would talk to me. A random girl saw this and asked my girlfriend if she was ok. This girl then notified a security staff member of the bar, who led myself and my gf to the courtyard area of the bar. While we were outside and arguing, I'm told I slapped her in the face. When this happened I was kicked out immediately. For the remainder of the night, I tried to get in contact with her while I was being berated and condemned by her friends.

My question for you is this: How would you recommend I go about making up for this complete loss of frame? I am absolutely mortified at myself for getting violent with a girl. That's something I've never ever even considered, and it only happened because I clearly have an issue with alcohol. All of my gf's friends (who were previously friends of mine) now hate me, they publicly berated me on social media trying to turn other friends against me, and while reciprocity with them seems completely out of reach I just want to convey to them how sorry I am for being violent. My girlfriend is being supportive, as she wasn't physically hurt by the incident, just rattled. Any advice would be much appreciated, I feel like a complete piece of shit right now.