You know you could also being physically unwell from staying in an abusive type relationship. I have had to finally admit that too myself that I think some of my health and weight issues are because I keep in a relationship that is bad for me and shove down the wanting to leave into my body. I even have a cough that gets worse when he is around or when I talk about him to someone. --No joke.

It definitely sounds abusive, and it isn't healthy if he is not sticking up for you to his parents. Which too me means he has talked to them about you and has agreed with them if they feel so comfortable as to say that to your kids.

I wouldn't let the kids see the grandparents until there is an agreement all sides that they don't say negative things about their mother.

But by not being abused verbally so much you might find your energy coming back and your mental and emotional well being coming back because you are not constantly either out loud or silently being attacked.