Here's my $0.02.
This has a lesson in it for you. I don't know what the lesson is, but I know I personally (now, after enough painful breakups) am very slow to jump into things with anyone. I really get to know them before I even go to their house or kiss them goodnight.
That little rule has saved me more than once. People are really nice and on best behavior on the first few dates, but they will usually hang themselves on even the tiny bit of rope I give them.
If they start talking about their past hard drug addictions or domestic violence or if they talk hatefully about an Ex or their family, or if they like to gamble or love porn or strip clubs, or whatever. Prison time? Smoke pot? Taking pain meds five years after an accident? Heck, I don't even go out with cigarette or vape smokers. Any untreated addiction or anger problem is a dealbreaker for me. If I jump into a situation where there is already serious dysfunction I end up mad at myself for not respecting my own spidey sense.
I don't know, are you maybe a little mad at yourself for not getting out sooner? Sounds like she was having more than a few difficulties in life. Those of us who are "rescuers or fixers" need to examine why that happens, too.
Maybe take a peek in the Friends & Family section.
Welcome to the forums.
https://www.soberrecovery.com/forums/#friends-family