Breakup

My bf and I got into a massive fight, like the biggest one we’ve ever gotten into. We’ve been dating 5.5 years so it’s been a while, recently we’ve been fighting a lot but I never would’ve thought he’d do something like this to me. We broke up I’m pretty sure, there is no way he would want to stay together after such a big fight. After the awful day we had, I was in bed at home sobbing because for what happened and because we broke up, and I find out from one of my friends he is out at the bars with his friends for barmagedon. I don’t know how he can be so okay with what happened that he is OUT PARTYING meanwhile I’m in bed distraught over him. I’ve never felt so hurt or betrayed in my entire life. I even cancelled our planned trip to Denver in January because if we’re broken up I might as well get my money back. Has anyone gone through something like this? He is my first and only boyfriend and we’ve been together since we were 17, were now almost 23. My heart is so broken I don’t know how to get up and function.