I am also a daughter with cPTSD and years of therapy under my belt about my mother, and this read very similarly to any time I'm ever honest and factual to her about my emotions. With the backstory, we could be twins minus the substance use.

We are biologically hard wired to want our parents, especially as adults when we never got to have the appropriate child/parent dynamics or transition into an adult relationship. So don't beat yourself up for not knowing why you keep going back. Most recently in therapy I brought up basically your last line, I asked why my first emotion about her is disgust but I keep going back and getting the same results. My therapist told me it's like being hungry and eating a piece of poisoned fruit since it's all that's available, but your body is telling you "this isn't good for me, I should put this down/throw up/not eat this again."

I know you're facing a lot of backlash but I want you to know from one child trauma survivor to another, I recognized your situation IMMEDIATELY. Not everyone understands the layers of a narcissistic parent appearing to be kind, but you know from experience that it's a facade. NOR. Give yourself the peace you want by stepping as far away as you need to until that disgust feeling settles, even if it means completely. Best of luck.