I was once in a toxic relationship. It was so toxic on both sides that it was hard for me towards the end to discern just how abused I was.
The slaps, pushes into furniture, constant put downs, being shaken off the bed, pinned to the shower wall after he beat down two doors to get to me, beating up male friends, abuse by his family...and so much in front of our children. I couldn't figure out what to do because the chaos was so constant I was sucked into a whirlwinded black hole of just surviving. This man who could at one moment be compassionate towards all other human beings but me and then in the next moment be railing at me for not keeping the house perfect for him had my love and hate totally infused into each other.
I left him, finally, but he stalked me for a year, threatened me and my friends. I still have to deal with him because of our kids, but I believe he is much better now and so am I. I understand why women stay because I was that woman.
And I understand people change. If you're in a toxic relationship, just get out. The next steps will follow. It will be SO HARD. You'll doubt yourself. You'll remember your own wrongs. You'll still understand your abuser and your own abuse, but you'll grow from it. You can be a different woman.