Overwhelmed by boyfriend and his family

I'm currently having to feed 6 mouths including mine and paying for all the bills. I asked my boyfriend to quit working his $15 am hour labor job because they wouldn't put him onto the schedule after being sick, so I thought he deserved a better job. Plus I was going to be going to school soon for a month and we only have one car and his work schedule was 3am to 11am, which wouldn't work. His mom moved in with us, she is paranoid schizophrenic so she has a limited income. She gives $300 a month for her rent and I pay $500 for the rest. I've been buying food for all of us and our 3 pets, driving us around, paying for other bills and I'm late on internet and utilities. I'm feeling overwhelmed and as if my boyfriends mom got tossed onto us because her parents didn't want to deal with her anymore. I start school the first week of next month, but I'm 21 and tired of feeling like everyone's mom