Anyone have this experience?

Mom was w/ Significant Other 35 years (never married, never wanted to remarry). They lived together off and on 8-10 of those years. She was diagnosed with Dementia in 2015 whether or not she told SO l don’t know. In 2017 she falls & breaks hip, after PT she decided to go to his house although not advised because of carpet, open stairwell in middle of his house, he’s extremely hard of hearing and there’s dogs without manners (no commands, under foot all of the time). August 2018 she comes to live with me and husband. I find out SO had left her (in March) at Dr appointment because she has me on HIPAA. I find out from her BFF that mom had written a card stating he struck (her months prior). This was a history when he came into our lives in the mid 80’s. It’s the reason I cannot stand the man. I witnessed a lot of abuse (physical, verbal, emotional) with their relationship. I wasn’t aware it was happening again/still(?). He has told my sister and me if we were to ever keep him from mom he would “shoot the both of you.” I believe it. In Sept 2019 while she was visiting him for a couple of weeks I received a text from our bank that the two joint accounts she & I had were “brought down to zero.” My husband calls moms SO and advises he needs to have my mom call me- her SO says “(moms name) is with me now, she is NOT returning to (your home/city) and tell K I am now POA.” I filed for emergency Guardianship and In the 3 weeks btwn filing and the hearing, he married her. 10 days after ceremony the GAL I hired interviewed mom and she didn’t even remember being married. We have the hearing, SO agrees to annulment claiming he didn’t know she had dementia and “it’s a matter of opinion” whether or not she has it. During this time I recognized and have honored the fact they have been together for many years, it’s moms desire to stay with him the majority of the time. It was agreed there would be in-home healthcare 2x a week along with visiting and phone calls by us when and how much we would like. And she would come to my house one full week a month. Three weeks later when I petition the court for annulment he shows up with attorney hurling allegations at me that I’ve coerced mom into gifting me property (it was our restaurant SHE and I worked tirelessly on) and another property sold to put addition on to our house for her to have an in law suit.
All of the while my family know what is going on, no secrets. They support me 100% because they know I’m doing what’s in moms best interest. We didn’t see/speak to her for almost 10 months. When I would try to call he would hang up on me, the phone we provide for her is turned off. He has physically put himself in front of a door at the Dr office not allowing me (her Legal Guardian) in. He’s not taken her to appointments for f/u on legion on her brain, neurological appointments etc. Nov 2020 they have a car accident. She’s in Hospital for 84 days- discharged on hospice. Brought to SNF at my request because she was a two person assist. My niece and I settle her in. I allow Husband to visit next day (3x a week). He shows up w/his attorney demanding to see her. I had told SNF husband could come but he couldn’t bring guests. The audacity of the attorney has been atrocious. The SNF stopped allowing her husband inside visits because he would wheel her to nurses and ask DO YOU WANT TO GO HOME, and she would say yes. He would try to get the attorney on the phone or bring papers in about his rights as her husband. I don’t know that he ever asked how she was doing. Over the last year & a half the attorney advised mom & her husband to not speak to me. I’m her legal guardian. AND she has DEMENTIA! Mom starts doing well at SNF she’s taken off of hospice & put on PT.
8 days in she falls and breaks her hip. Now she’s back at SNF for 6 days and she’s sad and not thriving. Meanwhile during all of this from the last year & half I’m about to have a breakdown or heart attack. We have a court date coming up in April.