My abusive grandmother refuses to remove herself as my representative payee on my Social Security to keep me financially trapped. Any advice on removing myself from the situation?

My grandmother has always hated me and this is no exaggeration. I am 20 years old with PTSD thanks to her. I’m struggling to escape from her narcissistic abuse. When I was young (between 6 and 12) she was physically violent but thankfully is not anymore. She lied to department of child protective services and said that I am the abuser even though I was covered in bruises. Her golden child, my brother Mathew, helped my grandmother frame me by recording the part where I defended myself. Conveniently, no one recorded the part where she attacked me. When I turned 13 is when the hatred begun. I didn't have any menstrual products when I started in the middle of class thankfully, my teacher let me go to the bathroom because I felt something weird. I had to ask my grandpa for help (both of them legally had custody of me because they damaged my biological mother to where she can't even take care of herself or any children). After that, my grandmother would become so angry with me and would always complain about how I smell. I tried to be a loyal, good kid but all of this changed when I entered high school at 14. I started 9th grade and I passed all of my classes. My grandmother tried to project her faults onto me; how she regrets having any kids and wishing that I was aborted or that my fetus got recycled by the Chinese to turn into birth control pills. At this time she had to take a medication because if she didn't it would cause seizures. Thanks Effexor for making my grandmother an addict. My grandmother frequently tells me to "go f*ck myself" or to "go to hell" and one time even told me to “kill myself”. She bullies me and says that I have no friends when that is not true. She became extremely jealous when I received my high school diploma and enrolled for Pelissipi State College.
My grandmother is a sick human being she's trying to drive me to suicide (she even admitted that my sister-in-law killed herself because of her). My grandmother has done nothing but start arguments with me. I can't even get on the phone with Pelissipi to get my log-in information because of the constant yelling in this house. She refuses to get psychiatric help. She caused my grandpa to have a heart attack. She has pinned everyone against me by telling lies. She even tried to lie to the cops about me. She keeps threatening to file false police reports against me. She refuses to remove herself as my representative payee on my Social Security to keep me financially trapped. My grandmother uses her medication as an excuse for her horrible behavior but this is straight up narcissistic abuse. I have called several independent living departments that kept giving me the run around. I would report her to the cops but she will lie to them and I don't want to go to jail over this evil toxic granny's fabricated evidence against me.