Im at my Witt's end with my in-laws..Help! What would u do?

My wife and our 5 kids have moved to a different town, so she can finish up school. Well, her mother also is going to the same school, so is her 22 yr old sister. We all decided that it would be in every ones best interest to live under one roof and split the expense's. The have only 6 months more of school left till graduation. We got a two story house with more than enough room for us all. Well it all Sounds good but it has been hell from the get go. My-mother in law and sister in law are always complaining when it comes time to pay bills.So to remedy this we all pay equal shares on all the bills,we Split it 4 ways. Sounds good right! Well that's not all. We also agreed t go 1/2 on food and cleaning stuff i.e laundry soap, toilet paper etc. They never have enough money to fully pay all the bill's or help out with anything else. So i pick up whats left. I get paid monthly, well enough that i can support my family and a little extra Thank GOD. Let me also explain, that i am disabled, currently waiting a kidney transplant, and go to dialysis three times a week for 4hrs and 15 min a session. so needless to say on those days i come home extremely tired. While they go to school and work i do all the cleaning and cooking. At first no problem. I wanted to do my part. There is nothing medically or otherwise wrong with my mother in law or sister in law that would prevent either of them with helping around the house. But they do not. They dont cook clean or 1/2 the time have enough cash to pay all the bills. My mother in law is always bitching about this or that. I used to love to cook but here lately I hate going into the kitchen to cook because it feels like i have 2 extra kids to support. While im cooking there will be nobody around with little things like hey, i know your tired can i help out? even if it were a bold face lie with no real value. it would be better than nothing, but just about when it's time to plate the meals here they come all smiles and ready to eat. Then after were done they get up and go back to there rooms. They even have the gawl to just leave there dishes on the table as if im there slave. My wife and i are constantly fighting over this. but she always calms me down telling me just a little while longer, and i hold my tongue. But i am getting sick of it. my sister in law treats my kids as if they were her servants. Instead of getting things for herself she calls my kids to get her for her. Since we are on a very limited budget, we dont always have left overs for seconds, i have watched my sister in law take food of my younger kids plates. now dont get me wrong we eat very well, its just somtimes i dont make enough for seconds. My wife has gotten on to her for it, but it goes in one ear and out the other. When ever im too tired to cook we order out, never once have we forgot to get them something to eat, My sister in law will go out and bring home something just for her and when asked why she didnt bring the kids something or eat it somewhere else, she replies, They are not my kids. She'll even expect to eat again when supper is ready, My gosh! My mother in law and sister inlaw cant get along. My sister in law has no respect for her, and is often times than not throwing a fit and crying like a little baby. so when my mother in law is mad she picks fights with my wife which gets me very mad. But i hold my tounge. My mother in law never hold's her tongue, she says what she wants when she wants. My question is. If she or her daughter dont help out, Do either of them have the right to grip about anything? They get there house cleaned there meals cooked and served. bills paid and sometimes there laundry washed. My sister in law is ruthless for throwing her clothes in the washer while i wash a load or two. i dont realalize it until i fold them. My mother in law walks around and is always saying this is her house, but the truth of the matter is if we move out she wont be able to afford it. I want to move, my wife thinks we can make it till graduation. I hope so. Help, help. please help. What woud you do if you were me?