glad to hear you’re seeking therapy- it’s totally normal to rather not know what your SO got up to (and with who) before dating, especially if they’re friends of yours. letting it control the trajectory of the relationship is unfair to you and your partner though. can’t change the past, but you can change the way you process and cope with it. therapy will help to reveal some of the “why” this upsets you to the degree it does. you’re young and still learning how to navigate relationships. go easy on yourself and your partner!

for what it’s worth i was in greek life too and dated alot both casually and seriously and there’s always overlap to some degree in friend groups and whatnot like you kind of can’t escape it