How do I keep my sanity while my mother and father in law live with me.?

There is so much detail to add but I will try to keep it reasonable. I've been married for 16 years with no children, my husband basically is a Moma's boy, we lived practically next door for the first 6 years, then moved about 80 miles away. My husband called daily sometimes more than once. I had no say my holiday had to be with his mother and father, never mine. later in years I attempted to make plans to share holidays with my sister in law. recently we bought our first house and of course it was an absolute no, to have the holidays at my new home. Along with a huge amount of disfunction with my brother and sister in law. My father in law was diagnosed with parkinson's. There was so much going on with nightly calls and mother in law's depression and crying and not to mention my own husbands not dealing well with this sickness, we decided that we did not want him to end up in a convalesant home. And with no help or communication with my brother in law 7 months after finally getting my new home we decide to move the in laws in. Needless to say it has caused jelousy with my brother in law, 2 months later, My father in law told us that his now new doctor did not believe he had parkinsons and started to low his medication, we seen a hugh turn around for about 2 to 3 weeks, he was like his old self, the next thing I know he has another doctors appointment and they say now he might have it. He of course came home depressed started to self medicate himself and then says he wants to kill himself. My husband of course after work sets for hours on end trying to entertain and console them both. especially his Mom. Working together as women I thought she would be a little more independent and help with the cooking, she wont even read a letter, write a bill she has always been needy, weak and so unbelievable dependent on her husband. but now it's me who handles everything, including all my own bills, and problems, along with working more than 40 hours a week and driving and dropping of my husband. Yet every one in the house treats her like a pricess, I'm stressed and tired. I feel that this good deed will effect my / our relationship from now on. We argued this weekend and they have threatened to move out. Of course I feel guilty I wish I could just put on an act and pretend I'm happy but it shows all over my face. It's especially due to the lack of privacy.