I slept with a married man

Context I'm F(22) the guy I slept with is M(30)

Okay I know what I did was wrong and to be honest I doubt the reason for why I did it is even justified

So I worked at a restaurant before the guy I slept with (R) came to work there with his wife, before sleeping with with I was really good friends with his wife (I didn't speak to him) I cared for her and we got really close, until one day she started being mean to me and ignoring me for no reason, so I just let it and didn't say anything to her.

Then one day the manger of the restaurant told I won't be working there anymore and they'll call me if the need me to come in, after 3 the wife quit and I was called

One day I went to buy a drink (for personal reasons, I was going through a lot I didn't care what I did at the time I just wanted to bury my anxiety and pain in something) and R asked me to buy him one too

I bought the drinks for him and his friend and he paid me back, the he asked me if I wanted to drink with him later (I knew exactly what he meant by that, and well I was feeling petty and hurt by how I was treated by his wife, and said yes)

We drank more after work in his car, after a few more drinks he took me to a quiet, dark place and we did it in his car (honestly I felt like I messed up the next day, so I avoided him for a while despite him trying to talk to me)

After a few days something in my life didn't go well at all, and I ended doing the same thing again, it kinda became a way for me to run away from my problems, to distract me from the fact that I was at the edge of life and with one wrong step I'd hit rock bottom

(To be honest his wife at one point did come and see him, and she still treated me terribly, so I ended up feeling so justified and happy with what I was doing even tho I knew it was wrong)

I did come to care R a lot despite knowing he didn't care about me, I ended up leaving the job and I'd still sometimes take time to go see him, but I had enough, I enough of him telling he cared and never once coming to see me, so I told him as much and told him that, that would be the last time I'd go see him

That if he wanted to see me that was on him, but I wouldn't take time to go see him anymore, now I'm just have this weird feeling in my chest that I can't understand, because he told me he'll let me know if he wants to go see me

I'm not sure how to feels, if I'm sad, or happy about how I left things, because I wished him the best and I think I did everything I should've

I realize I'm a terrible person, I'm selfish and selfcentered, I know, I know, but know how to start fixing myself