I 19F cheated with my bf 24 M of 1 year and a half now

my boyfriend and i have been together for a year and a half now. we love each other deeply and we only want to be with each other forever. i (19F) met someone through instagram, this guy messaged me trying to hit up on me. after a small conversation i blocked him because my boyfriend told me to ignore him, yet i actually gave this guy my phone number so he started messaging me on imessage instead. i told him that i have a boyfriend and i want him to be my friend so i asked him to be civil. i thought he is like a therapist type of guy so i referred him as that and seek him relationship and personal advices, i thought this guy could be trusted so when he invited me to hang-out with him and his girl (he is in a poly rs) i agreed. i thought it would be safe since i thought of him as a friend but after smoking for 3 hours and i am very much intoxicated (to the point of blacking out) when i went to bed and rest (in their unit) he started kissing me and he put his thing inside me without consent.

afterwards, i went home and told my bf about what happened after 2 days of the event. i blame myself for everything. my boyfriend wants to forgive me and get back together (we decided to cool off unless i am able to fix my issues) i don’t know where to start. i am friendless and i only hang out with his guy friends and him.

i don’t have any friends, which made me prone to such kind of things. for now, i want to reflect and do everything i could to change. i am truly desperate to become a better person. I really want to make amends.

How do i cope in this kind of situation ? please give me an insight, any advice would be appreciated.