Dear tensilestrain and frog, I've tried on many occasions to shower in the common toilet and I even told my MIL it's because I don't want to disturb them as they are resting in the room. And every time after I shift my shower amenities out into that toilet, she will shift them back into her toilet. The family uses the common toilet for laundry, and it's where they place all their dirty pails, etc. so they don't want anyone to use that toilet to shower.
As for dinner, I have always offered to make dinner but my MIL has declared right at the beginning when I first moved in that 'I own this kitchen okay. This is my kitchen, you all don't come in here and do anything.' So from then, I knew I was not allowed to even cook if I had wanted to. And I tried to tell my husband we could buy dinner back so his mother doesn't have to always cook, very tiring for her. He insisted on letting his mother cook and there's really nothing I can do about that.
As for the water, the moment I discovered there were always particles in the water, I offered to install a water filter system in the house (and will pay for it). But I got a scolding from my FIL - he says I'm wasting money. I've tried to boil my own water, but my husband asked me why I boil when there are still water in that container and his parents also came to ask me not to boil when there's still water - so it's hard for me to boil my own water and have my own container in our room. Initially, I washed the container every morning and my husband also say I waste water because I will rinse away the water that's still inside.
That's why I'm hoping we can rent a place our own outside so we can work on developing our marriage without his parents around, and then have children.