Autistic child living away from home abusive help

Hi im shaz 

My daughter has lived away from home since birth ( please don't judge)  I have cfs also have a longstanding issue with my back causing bad mobility problems 

My daughter is 14 with autism and pda 

So an explanation of the situation 

My daughter lives with paternal grandmother and during visitation has become increasingly hostile and unpleasant with me, I never shout apart from one situation which I will explain soon I try my best to do what she needs wants etc but it came to a point earlier in the year where my eldest daughter after 6 years of her living with her dad (court ordered) turned up at my house ages 18 with seriouse anorexia nervosa and informed me she was pregnant, my eldest asked to come home she's doing better and baby was born healthy at term 

The issue came in when the room my youngest stays in when she stops over became unavailable to her she was barely staying over one night in 6 week I got hurled a lot of abuse but the language used was that of a grown adult and legal terms she can only have got from grandmother I feel like I'm being abused by paternal.grandmother through my autistic daughter she won't talk to me grunts growls or is just absolutely verbally nasty towards me when my daughter came up after discovering the room  was needed and her screaming down the phone at me for 2 hours I lost my temper it was my birthday the day after as well and I eventually lost it i called her a spoilt nasty brat and she said I didn't treat them equally (my eldest could have being hospitalised and lost her child without intervention) (my youngest mimicking words during this about court orders etc and calling me a bad mom ) I eventually told her to f off first time I've ever ever shouted or sworn like ever 

I went through this treatment at the hands of my eldest daughter and my sons dad basically parental alienation bullying and abuse I feel this is being repeated as it's only me who's targeted with the nastiness and have being told my paternal grans daughter she's heard me being badmouthed herself I'm good friends with the paternal grans daughter 

Child's dad doesn't want me to co tact social workers but I'm at a loss of what else to do as this isn't just a breakdown in a relationship it's gotten to a point where I feel bullied 

Gran has lupus I have diagnosed cfs suspected fibro and can't walk without a stick short distance and realistically need a mobility scooter for long and I'm also being told I'm crap because I'm disabled daughter states well nan says she's got similar and she can do it (nan is able to walk independently of mobility aids) and I believe she's telling my daughter I am not sick or stating because she's ok I should be too I've tried explaining to my daughter I'm also disabled as she gets told her autism makes her different so does my illnesses but she can't seem to accept this 

It's resulted in no contact and her dad not the same dad as eldest two wants to see her desperately I personally don't want to see her untill I'm not being abused for being me 

Any advice would genuinely be appreciated