Thing is, you DO have choices here, and you DO have some amount of control in this situation. Right now, you are choosing to remain in the relationship, hoping it will improve.

The guilt and shame come from a codependent position. You mentioned codependency at one point (I think). When we are codependent, we think that it's our responsibility to take care of someone else's issues, even if it is harming US. In order to get "unstuck" is to recognize & acknowledge the codependency and to get help for it. As long as guilt and shame are present, it will be hard to unglue yourself.

I had an abusive fiance years ago. He got drunk frequently and would go on abusive rages at me. He stole money from me to support a secret drug habit, and he was doing drugs behind my back, then getting drunk and going on these tirades. He also refused to get a job and help me financially, so I was stuck supporting him 100% of the time. After 3 months of enduring this dynamic and this toxic situation, I finally got fed up one night and kicked him out of the house,. He had been homeless just before we moved in together (his family kicked him out, so I took him in). He became homeless again once I kicked him out, but now miles and miles away from his home town. I knew once I did this that he would have no place to go. Now, if I had remained in a codependent position, I would have stayed and endured the abuse in all ways and I would have continued taking care of him. AND I WAS taking care of him. I was more like a mother to him than a partner. But, I was healthy enough to say "enough is enough" and I kicked him out, regardless of the repercussions for him. I didn't care anymore and I knew he had enough street smarts to survive. I needed to survive too, and I did.

I hope this story somehow helps you, but if not, please disregard.