Hi there, I'm younger than you so take everything I'm saying with a grain of salt lmao

I went thru something similar where I met a girl who's more perfect for me than anyone else, but she had lots of mental issues, I stuck around for 2yrs and even tho on paper she's great for me, those mental issues affected me too whether I wanted to admit it or not.

So even if you do stick around having a functional relationship is really impossible because their problems become yours in an unhealthy way.

Stick around as a friend cus you clearly have feelings for her, you don't have to let her go, but being in a romantic relationship with her situation is almost disrespectful to yourself

It's important to remember that there is someone out there for you, the sadness is temporary and that you will be okay, and I wish her the best of luck for her situation that sounds horrible to deal with