I bet she really didn't know what you meant by that because she's deeply in denial about real life. Whatever trauma she experienced as a young child has crowded her good judgment.

I know what it's like to distance away from a mother. It's hard work. It might help if you make up your mind on what you want from her, if anything at all. It's great that she's been there for you. With that I'd say the favour needs to be returned. If she's being verbally abusive, I wouldn't lean on her for "support". Maybe you're giving her mixed messages. Either she's in or she's out.

I limit my interaction with my mother to email. I'll attend important family gatherings only (100th bday celebration, a funeral, etc). When her husband passed away (during covid), I called her and spoke with her for 3 hours. She likes to monopolize conversations.. but I set that aside because someone of importance died. It's hard work but she's learned to accept my distance. It's been about 7 years now.