Wow, Rose, your "toxic family" is really behaving in an awful way towards you. You have my sympathies.
When I had little ones at home I did the no contact thing also. I did it _completely_. Banned _all_ the toxic family members from having anything to do with my kids. And yes, it was a major battle with everybody. From your post it sounds like 99% no contact is just not working for you, it sounds to me like you relly need 100%. That's the only thing that worked for my situation.
What I don't see in your post is any mention of what kind of support _you_ have in maintaining your boundaries. Where else can your kids go to keep them busy? I made extensive use of the neighbors. Are you going to meetings of al-anon? Are you taking your kids to al-ateen and al-atot? If there aren't any, have you tried starting some meetings for the kids with other members of al-anon. How about a family therapist?
Whadya think?
Mike