How do I deal with a Mom with narcissistic personality disorder? Or borderline, I can't tell?

I take care of my 81 yo mom and now live with her to get out of debt...I am happy to do that and there are caregivers who also help out...We have a history of conflict and it seems to be getting worse, especially when she calls 4 times a day and I feel pressured, guilty, angry and helpless just because of her demands and her sensitivity..i can't say anything or express feelings to her or she'll use it against me...My therapist tells me not to take it personally but it's difficult...I feel like i'm going crazy and plan to join Alanon.