Abusive mother and relationships have destroyed my mental health and grades

I’m (25) finishing my master’s and recent events brought back a lot of issues I thought I moved on from.

My mother was always manipulative, mentally and emotionally abusive. Recently my grandmother, who she lives with, had health issues come up and she needed help getting to appointments. I had cut my mother out of my life about a year ago but my grandmother isn’t great with phones and my brother (17) doesn’t need to be stressed by me asking him times I needed to be home from college to take our grandmother so I have been in touch with her again. She has used this opportunity to continue a lot of what she had previously done and I was mostly able to ignore it until she made a few remarks about something I thought she didn’t know about. A year and a half ago I got engaged to someone I had been close friends with for years and dating the prior 2. It ended up falling apart, she was raped while visiting family a few states away and spiraled, I blamed myself because it occurred when I was supposed to have been with her but coworkers quit and left us shorthanded so I picked up some shifts and planned for a short vacation to visit her family for the holidays and she knew and agreed that it was a good idea. In a previous relationship my girlfriend at the time lied about being pregnant so I would stay, the relationship hadn’t been going well for a while. She drugged me when we went out for drinks with some of her friends and woke up with her on me. I left after that incident and never heard from her after blocking her on everything, the last I heard she had been deported because she was here on an expired student visa. My mother basically said that it was my fault because I ruined her life and my ex’s. Normally I can ignore what she says and has said but this time was different, I haven’t been able to stay home alone, work on assignments without becoming a nervous wreck or feeling like I need to shower because I feel disgusting. It’s heavily affected my grades and I’m supposed to graduate next month but the way I’m going I won’t, I need to talk to my professors about my situation but I feel disgusted with myself and have it in my head they’ll ridicule me and haven’t opened my email the last 2 weeks because of it.