Hi there,
I'm in a similar situation to yours. My family (parents, siblings, grandparents) all live 500 miles away in the town I grew up in. I love my family but there was always some kind of drama so I liked my separation. However, 11 years later and getting married and having a kid I thought it would be a good idea to move back home. I moved home last December. But the drama started immediately and I quickly moved back to where I was living.

My parents can also be toxic for me. But I love them and my siblings and in some way I want to be there for them. I'm not sure how old you are, but when I realized my parents weren't going to be around forever it really made me more inclined to deal with the crap. It's definitely tough trying to set boundaries but still trying to have a relationship with your family.

Maybe you can write out specifically what things you are willing to do to help your grandma. Like making doctors appts. for her researching her symptoms. You could also do the same for your parents if they ever need care. That way you know ahead of time what you will and will not do. That might give you some comfort in know to what lengths you'll put yourself out there. Hope that helps...