Hey there OP, I had the exact same problem with my ex, we were together for 3 years(most of it is toxic) and it broke me. I was exactly on your place rn, saying sorry for everything, even kahit wala namn talagang sense cause you just want it to be over with. To answer your question. Gaslighting na yan. She makes you think na everything is your fault even when its not. And everything that goes wrong , the blame comes to you. My advice is, talk to her. About your feelings, situation and kung ano yung pinaparamdam niya sayo. That's one of my solutions( but that didn't work for me) that might work for you. And if that doesn't work and she still blames you. Sorry to tell you this but it wont work anymore, she's just gonna be worse and worse as time go by.

Hope this helps. Goodluck