I disagree with everyone.
If you're struggling to pay your bills and living with your MIL out of necessity, then a FT job takes priority over school. Sorry, but it does. It has to - bills don't pay themselves, and the suggestion to take out extra loans to pay your living expenses is ridiculous and irresponsible. Believe me, it's going to suck bad enough paying your current student loans 10 years from now - student loans aren't free money, and paying off loans (with interest!) that you took out to pay for groceries 10 years ago is going to suck even more.
Does your program require that you go FT, or could you drop to PT for a little while? Is it possible to take a semester or two off without being kicked out of the program? I would make getting a job my #1 goal, followed by getting the hell out of your MIL's house.
I worked 30 hours/week through most of my undergrad, and worked FT during my Masters program. My husband went to undergrad PT while working FT and also worked FT in grad school. Sure, it's hard.....but it's easier than playing house under your MIL's roof.