Well...how do I begin my tale?

It all started when i got engaged to be married, my husband to be and i were still finishing college so my mother in law let us stay in her summer home, which is in the mainland, until we stabilized our financial situation so we could move out into our future home.
At the time, I thought that this move was a blessing...little i knew that it would turn into a curse...
My husband has a brother, at the time we were living together, his brother started doing drugs and kept bad companies...my mother in law, talked to us, and told us that he was going to move in with us because his counselor said he had to change places for a more stable environment.
I took it like a grown woman, i knew my brother in law and apart from all that was happening, he was still a pretty decent guy.
But when he got here things were horrible, he didn't clean after himself because his mother used to do that for him, he had no notion of chores....i blamed it on the transition period and started picking up every slack.
We got married and two or three weeks later i cleaned vomit from the bathroom floor.....he had been partying the night before and left it there for me to clean...at this point i snapped and confronted my husband. he was supportive and talked to his mother....the answer wasn't what i was expecting.
She started implying that i wasn't clean and that her house was a mess because of me....i broke down and told my husband that we needed to do some sort of chore list because i couldn't keep everything spotless and focused on everything else (a.k.a school and other health issues).
The chore list is done, but he keeps not doing anything...the only thing he had to do at the time was clean his room, turn ion the washing machine when its full and take out the garbage....i did all the rest...but it still wasn't enough, and it wasn't getting done.
I gave up, that summer, when my mother in law came to spend her vacation with us, she was chocked with the amount of garbage that was in the house, she sat us down, like we were children and implyed that we were pigs...i had to listen to the whole thing quiet....the whole time...
her plan?
She now assigned tasks to us all, each one of us would have to clean an area of the house, my brother in law kept the kitchen, she looked at me when she mentioned the kitchen, i turned it down because someone needed to see how much i have been doing for them....
So my brother in law kept the kitchen, and this is what i have to live with now....i can't eat at my kitchen table because it is cluttered with garbage....even the floor is full of water bottles...i am a complete mess...
We have intervened, we tried to reason with him but nothing, he just doesn't care. he started dating and spends most of his time with his gf in his room....he only cleans the table when they want to have dinner....she gets in our house and doesn't even talk to us...she even blames his drug addiction on us....
My husband and i love him, we would never do anything to hurt him and he knows that, but he uses us as alibis when he messes up and makes us look shady and that is very hurtful.
Yesterday i finally got the nerve to step up and my mother in law no longer thinks what she thought about me, instead she told him that if he still doesn't do anything i should do it and he should pay me.......
She also said that she talked to him and told him that if he didn't do a least the minimal around here that he would have to start looking for a new room...
He doesn't even pay INTERNET or cable, he pays no bills...we do...

I accepted the paying solution because i love cooking and would like to have a decent meal with my husband, on a table, instead of in front of a tv....he also stopped doing laundry, i have to do it, fold it and put everything in his room....

I don't know what to do, if i say something to my mother in law she starts judging me and doesn't even see what she has done with my life...if i talk to his brother in law he starts calling me names and being really abusive...
My husband is in the middle, I'm on school break so i have more time to clean, we agreed that he doesn't need to do much, only take out the garbage because I'm at home...but i'm scared, school is almost here and i still haven't got some peace in this home.....................

So million dollar question is, what should i do?