How can I get a "Personal Care Contract?"

I have seen on several posts that a personal care contract will save future family and estate grief and greed, but don't know how or where to obtain one, please advise me.
For the last 3 years, which happens to be the first 3 years of our marriage, my husband and I saved my in-law's house from condemnation by shoveling the hoarding and filth and making home repairs from 30 years of leaking roof and "full rooms" issues. His parents can't stand each other and if it weren't for her image at Church they would have divorced 34 years ago. My husband and I have no extra money because of my health problems, but with hard work and bartering we created a beautiful home for them to live their remaining years in. The problem is his brother/sister-in-law and his sister who all live locally, none work and none came over to help us, even for one minute, even though we worked full time during the day then till dark at their house and dawn to dusk on weekends. Of course now the brother and sister are "concerned" they won't get their share of the inheritance. Husband and I are clearly and legally to be the caregivers for the Father and the upstairs has been converted, at his req