AIO for seriously struggling mentally and not being able to deal with my gf's mental struggles ?

Hey, the title sums it up but I'll add details. Know that I'm gonna touch about pretty heavy topics

I'm a 26 yo woman and I currently unfortunately live in a dysfunctional and abusive/toxic family, i have been my whole life, i can't afford to leave yet. Life is complicated, I also have endometriosis, can't work in anything like I want, and finding a job is hard. Mentally it's been difficult for years, as my 65+ yo dad is cheating on my mom for so many years and he contacts young women, we suspect him to talk to minors too but nothing is sure. No need to say that i'm in a very bad environment and i just struggle mentally to survive in this mess everyday

I'm with my gf (25 yo woman) for a bit more than 1 year now, she also has it rough but I can't share any details.

She got tiny episodes of dissociation when we were together already but it was manageable. Currently it's terrible at her job, her landlord is going ape shit, her roommate puts lot of mental charge on her, there's just too much. Yesterday night we were supposed to share the eclipse in Europe together, she told me she felt unwell, i thought she needed some space. But generally she answers after 2-3h, this time I haven't heard about her for almost 12h until 3:30am. She told me she had a huge black out dissociation which is exactly what i feared, even more since she's alone now because her roommate when to a trip.

I know this might make me look like being selfish but honestly I don't have the shoulders to deal with things like this on top of my own problems. She doesn't have any therapy for any of her struggles and don't actively search for any even if she's not against it. I don't have either but i would love that and try my best to get it. I'm already exhausted by my life and I told her when we got together that I wasn't sure I was ready to be in a relationship because I'm not in a good situation mentally for that. I wanted to try anyway but this happens again. 6 years ago we tried to be together for the first time and she was already depressed, it was dragging me down as well. Now it's happening again and i have no idea what to do.

I know it's not her fault, she's the first to struggle with that, but I struggle a lot emotionally because of my own experiences. Being left in the dark for so long when she hates when I disappear for 2h felt very unfair but most importantly I was super anxious something happened. I'm just fucking tired because all of my stress is caused by drowning in other people's stress.

AIO for placing my emotional needs first when she just had black out dissociation ? Should I even be in a relationship since I'm not feeling capable to be there for her in times like these ?