What should I do!!

So here's the thing I've met someone 2 weeks ago on a bar, (Friday) it was my first time there—he's a cousin of a friend. I didn't really know how we hit it off, but I'm a flirty drunk so maybe that's why. We kissed and more that night... Do it again the next day (Saturday). Then we started DMing e/o in IG and such.

You see, the problem here is we're both in a relationship at the time we did it, mines in the brink of distraction (it was super messy and toxic) and I ended it with my boyfriend the next day (Saturday morning). So yeah we were talking and such while we're both aware of our what's going on on our relationships, he's so sweet, he takes care of me and everything. But we only talk when it's night cause I'm basically the 'other woman'. NEVER IN MY LIFE I PLAN TO BE THE OTHER WOMEN AND I RESENT CHEATING SO MUCH, but here we are. The guilt is eating me so much, so a week after we met again due to a unexpected gathering with our friends, and I ask to STOP EVERYTHING but God knows I want him so much. We're both drunk at the time he just kept on saying yes yes, but we still did it, then we had a very small casual talk, then goes home .It was the last time we've seen and talked to e/o. He soft blocked me on IG, I guess that's fine but why is it only me? Why can't we be just civil and such.

Tomorrow there's a possibility that we'll see each other again and I don't know what to DO!! SOMEONE HELP ME