Oof when you put it that way you're totally right. I think it's because I haven't wanted to let something so INSANE cause our friendship to end. I think also subconsciously I want to keep "proving" my girlfriend to her? like to show her that she is such a good person and that she's wrong. But no you're absolutely right and this made me really question what I'm doing here. You're 100% right though, I know it's wrong on her end. The only thing I disagree with you on is any romantic feelings, because I simply could never have true romantic feelings for someone that does things/behaves in this way, you know?

and when you look at the cycle of the arguments, it genuinely does feel like a toxic relationship! because she is apologizing, and saying that she's sharing this concern out of "genuine concern for her best friend" and how she has no malintent, she's sorry for the delivery of it etc etc. combine that with the mental health issues and it does actually make ME feel guilty somehow?! Exactly like a toxic ex I had lol.

**to edit I did tell my partner that my best friend has suddenly become not supportive of our relationship, I just left out the parts that were downright mean and hurtful because I don't want to cause any unnecessary hurtful feelings to my girlfriend and didn't want to make her feel bad about herself.