Help!

Okay im gonna start with some backstory.

My sister was born with cp. she is unable to walk, has limited upper body motor skills (can do simple controller things, and can poke her touch screen to select things at a fair accuracy), has difficulty with speech (ive been around her so long i can understand her sounds after a few guesses at most), cannot feed herself with utensils. Is currently in adult diapers and needs changed. Nothing wrong with her upstairs, she has always been bright considering her battle, if not a little socially or developmentally younger. (She is 23 now). Her legs are atrophied a bit because w sit is the only way she could stay balanced. And up untill a couple years ago shes been a relatively happy person, with great family support. Her dad hasnt been in the picture for a while. He has been known to have depression, but gradually stops contacting her. And over time she has felt hurt by this. It started with ceying and eventually tantrums. Normal stuff really.

This is where the problem lies. I left my family and moved across the US to pursue my own life. I left her crying at the airport, and sort of feel like part of this is my fault. But about six months after my move she started trying to hurt herself and use nearby cords to attempt to strangle herself. After my mom pursued doctor help they prescribed her pills for anxiety and such. These kept her sleeping 12-18 hours a day and groggy and drugged up the rest. My mom opted for other alternatives but after 2.5 years nothing is working, and her fits come more frequently. Shes even started to become violent to the point where my mom has to hold her down, and cannot sleep or leave her for any period of time.

When confronted when she is relaxed she claims she is sorry and honestly it sounds as if she is another person entirely. She hangs on to her father issues too much and i really dont know what to do to help her. She loves listening to music, reading, animal crossing, and even did her own fan-fiction.

Has anyone else out there been in a situation like this? What do we do? Im thinking at this rate there is no hope, and the best course of action to save the rest of my family members is for my mom to give her up, not that she likely ever will :(. Good Resources or suggestions appreciated.

Maybe i can get her to play some other games? Does anyone know any that she would be capable of playing? She liked animal crossing, i figure stardew valley is another good option (the cave might be challenging though). Maybe life is strange? Pokemon would be good, but handhelds just wont work, emulator or the crappy spin offs are the only options there. She owns a wii and a relatively out of date pc/speech device. But id be willing to buy anything if it brings her back.

Tldr My sister has CP. and tries to hurt/kill herself and others in fits. Need help bringing her back to her loveable self. Maybe some games that require no motor precision, bonus if they're online so we can join.

Sorry for formatting, on iphone.