I cheated and I regret it?

So before I start off I know what I did is completely wrong but I need to get this off my chest and need some feedback. My boyfriend and I are in a long distance relationship we’ve been together for 9 months now and I really like him. 2 weeks ago we had a party with a lot of people from my class and I was pretty drunk and had one of the guys I talk to hit on me. I don’t know why or what happened but I just gave into it and flirted back.. i was pretty drunk and I know that’s not an excuse but one thing led to another and I ended up making out with him and giving him a bj. I really regret doing this and I haven’t told my boyfriend yet and I know this is something that won’t happen again as well. I don’t know what to do.
I cheated and I regret it?
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