I know where you're coming from. When people say things like: "But she's your mother," you think, well, don't you think you should be making that point to her, not me? One possible answer when people say that is: "Exactly. She's my mother so she should have treated me better, but she didn't."
You are doing the right thing by protecting yourself. I think if anything you need to just refuse to have these conversations - tell people it's not up for discussion and that you do not require advice, then change the subject.

on your behalf. (((hugs)))