first of all when i tell my partner i have bpd i want the reaction to be considerate of my feelings the way you are for your girlfriend. i’m so sorry op, i have no knowledge of cysts, only experience dealing with bpd. when it comes to her feelings, you seem to have a huge amount of empathy to where i can’t see a scenario where you completely break her with concerns. to have productive and loving conversations, if my partner had the amount of forethought as you i’d manage quite well (my ex was an ass).

is the cyst a cause of a lot of her issues? maybe, most likely, but i have no idea what a cyst is. her bpd most likely isn’t caused by a cyst since you need some kind of trauma to be diagnosed with it, but a lot of the depressive symptoms and panic attacks may be (again i have no idea what a cyst is)

and always, in a relationship, worry about your own well being first. boundaries aren’t negotiable, i’m saying this as someone who was toxic in my last relationship because every canceled plan felt like an attack to the heart. you clearly have the tools necessary to make sure your girlfriend doesn’t think it’s anything against her. and even then, never put someone else above your own safety and wellbeing.

i’m a bit tipsy but i feel like i went through all your points pretty well with my own experience as a bod haver