im confused and hurt after a situationship ended 🤷‍♀️

im not sure where to start but ive been struggling over something that ended recently and i dont know how to process it properly. i was in a situationship that felt very genuine to me even though we never officially dated. we were definitely more than friends, there was alot of emotional connection, intimacy and late night talks that made it feel like something deeper. i opened up to him about personal things, parts of myself i dont usually share and he made it seem like he actually cared and understood me but its like the moment i told him i liked him, things changed between us. he suddenly became distant and over time things fell apart. there were times where id get overwhelmed or hurt and id pull away, kind of like ghosting? but he would always take me back when i came back. the problem was, he never really put effort in anymore like he would say all the right things but never showed it. it made me question if he ever cared at all or if i was the one ruining things because of how emotional i can get.

ive been diagnosed with borderline personality disorder (BPD) and sometimes its hard to tell whether im being “too sensitive” or if someones treating me badly so with him i keep going back and forth between blaming myself and blaming him. i feel like he took me for granted esp after promising he would never treat me the way people from my past did. i feel humiliated for believing him and confused because a part of me still wonders if its my fault. i hate how attached i get to people who give me so little back and i want to understand how to stop repeating this pattern. its exhausting and i feel stuck between wanting closure and wanting to move on so if anyone has been through something similar or has advice on how to let go without hating yourself for caring so much, id appreciate hearing it.

im trying to be self aware and work through my emotions but i feel like i keep looping through guilt, anger and sadness.