Need a lil guidance

My (20F) BP (19M) seems to be taking R very well. My bf is a very strong minded and smart guy. He’s basically my therapist throughout our whole relationship though i’m the one majoring in psychology lol..anyway given our age and culture im shocked we could be on the path to R as some people think a guy is weak to take someone back after betrayal. But hes no red pill ego guy ! We both understand our parents impact on us and we are a bit more mature then our peers.

I went to like a friend gathering at a friends house and kissed a old interest/friend a few times and we slept in the same room together when we all spent a night because it was thunder-storming. No sex happened just pretty much was letting him kiss me he was drunk and i wasnt exactly drunk but i wasn’t all the way there in terms of emotions.

The next day he didnt find out through anyone but me but i trickled the truth because of fear of loss i admit but he knows everything now it just basically took a week for me to even let everything come out of my mouth with all the shame and guilt i felt.

After alot of distance and arguments/talks we agreed to R and its been pretty good but ive been super stuck in my head. The shame, guilt and confusion of doing that to someone who i knew i wanted to be with until the very end. I figured out why i did it but i never seen it coming and i figured out how to not get into that state of mind and situation again but its been a month and a half and my feelings have been getting stronger for him and in turn making my guilt worse! We been together 8 months before D-Day !! yes we are um.. “new” but we are very close.

I literally just cant believe myself i genuinely hate myself. I dont understand how i can go against my own values and do that to him. There was no emotions for the AP or desire for them at all i literally just gave into attention. HOW IS IT THAT SIMPLE? I cant accept it idek who i am anymore and i feel like i dont deserve R with him. I literally should be in a coffin somewhere for hurting him. I literally end up in tears everyday thinking about it we weren’t supposed to have faced this at all. Im afraid of what i might do to myself honestly. How are you guys accepting R? How do u move forward knowing you hurt them forever?