Husband and wife refuse to go to nursing home/in home health care. Any advice?

My husband's grandparents are 81 and 89. He can’t hardly get around- he has a rope to pull himself out of the bed. He smells, refuses to bathe, won’t wear underwear and wears overalls for days at a time. Only has two teeth, can’t hear even with two hearing aides. He also wears his food all over him. She has congestive heart failure, very swollen, over 200 pounds, pees in a butter bowl (i know, ew.) so she doesn’t have to walk 10 steps to the bathroom. They refuse to eat anything that’s frozen or not freshly prepared.

I had been taking care of them but I’m no longer doing it in August because my mental health and my family is crumbling. She is like Dr Jeckyll and Mr Hyde. She’s nice and sweet to everyone else but when it comes to me and my mother in law she hollers at us and my 4 year old has to listen to all of this as well.

In Tennessee there is something called choices where it’s basically the same thing I’m doing but they don’t have to pay for it. From what I understand the state of Tennessee funds this is you are eligible. He has told her that they will take everything from you and they are refusing any help...but me.

I’m not going to be down there 24/7 365. Im not even blood. This is my husbands grandparents. She just got out of rehab due to getting down and weak. Should’ve never came home as soon as she did. Me and my mother in law are at our wits end. Any advice? Maybe this will show them when I leave they need this care but they will say they are dying at home, but taking down everyone with them. I’m over it and cannot wait till August.