my 85 year old mother

I think my mother is mentally ill. A thought? Maybe. But it feels like a circumstance as everyone in my family agrees. I’ve been taught to not “rock the boat” with her by my father. I’ve been programmed not to upset her because she had a terrible upbringing and has “issues.” Because of this I do a lot of things that I resent later – like recently getting down on my hands and knees and scrubbing a rock pathway in her back yard, also trimming thyme growing there by hand with scissors because she wanted it done. Afterward she told everyone who came to the dinner party she was hosting that she never gets any help. Ugh. So I don’t want to upset her but I feel bad about myself afterwards. I call her on a regular basis because I want a good relationship and because she’s 85 years old – I want a positive ending for us (like before she passes away). So I call her because I feel obligated to. I hang up and usually feel stressed and drained after the call. Therapists in the past have told me to limit my contact with her. I really don’t know what to do but I know I’d like to feel peaceful, less anxiety about her, and not resentful because I have several of my own health issues for which I get no support from her. I live alone – have no children and my husband has passed. How can I empower myself and still have a relationship with my mom? And why is it so damn important to me? Is this something that’s innate in us – to want our mother’s love?