Sitting in a home you shared together with so many memories is the worst.
I personally had d to move out, I couldn't be there anymore. Lucky for me, I wasn't on the lease even though I had been solely paying the rent for the past several months so she could get her finances in order (aka buy makeup, get her hair done, and pay random bills)
Again, this sounds like my exBPD, but in her situation with her boyfriend. He has been paying all of the rent, while she goes around getting her hair cut and colored and putting on her damn makeup every day, even when she doesn't leave the house.
freyed, I'm so sorry for what you're going through. I nearly ended up where you are now, a few times, actually. We never ended up living together, but we got close. With mine, it was a strange combination of her abandonment fears and her engulfment fears. I wanted to buy a place, rather than rent, which takes longer (abandonment fears), and felt engulfed the closer we came to actually getting a place.