Reds, well, I have to say that I read your post from the perspective of my children, all girls, ages 18, 15 and 13 and cried.
I was your mother until recently in many ways. The abuser, their father, was not sexually abusive, but he was abusive in all other ways, spiritually, mentally, financially, emotionally, verbally, psychologically, and physical. This went on in our home for over a decade. It steadily got worse and finally I had to get DFS involved and he filed for divorce instead of getting help. Even then, though, even after he filed for divorce and for all intents and purposes we were "free" I was still clinging to this man. Why??? I was in denial, I loved him not the behaviors, I am religious, I had hope for him and what could be, I thought he needed professional help and could be better. I clung to him and all these outlandish idealisms and kept encouraging my children to have a relationship with him, set some boundaries (ha! not that I ever could or did) and try to have a relationship with him because of the position not the man he is.
Well, my oldest gave up a full scholarship to nursing school and at 18 this year she got married, is pregnant and lives out of state. My middle one has been suicidal, depressed, and full of abusive rage for three-plus years, and my little one is well, lost in the shuffle. The younger two are in counseling. During the divorce process the court ordered psych evals and I found out a month ago that I suffer from PTSD from living in this abusive environment for so many years. Because of my PTSD and the poor choices I made in staying in this environment and clinging to an unhealthy relationship I literally have lost custody of my girls and they are in private custody now. I tell you all of this because as a mom I had underlying issues (depression, guilt, shame, undiagnosed PTSD, anxiety) that affected my thinking and my whole being.
Your mom may very well have the same issues and has a lot of denial about her issues as well). Your mom is a codependent. Reds, you seem like you are able to set boundaries. I applaud you for that. I am learning how to do that. You cannot fix your mom. You can only control your next concious decision. Do you want a relationship with your mom? Visualize that. What does that look like? Write it out if you have to. Then calmly set the boundary with your mom. I had to do that with my kids and they have done that with me. Their father is a big trigger for me. Just hearing about him affects me negatively. I have had to tell my children that I love them and want to be involved as ever with them in their lives, but that for healing for me I cannot tolerate any conversation that involves their father. Sounds like you need to do something similar perhaps or you will lose out on a relationship with both parents.
I am sorry that you experienced trauma at the hands of a parent. That is just not okay. My ex was abusive but so was I in staying regardless of how good my intentions were. I put my kids through years of strife and abuse by my choices. I have made amends to them, they have forgiven me, but it will take a long time to heal. Setting boundaries and sticking to them is vital in that process.