Vent!!

I am currently living with my mother. I do not have a job at the moment since I am on summer break and work at my college. I buy ALL the food in the house and do all the cleaning as well. I also raise my 14 year old sister since my mother is at work all the time. She constantly calls me lazy and a free loader and says I am living off her when she does NOT pay her bills. She spent over 1000$ to take my sister to Michigan Adventures instead of paying our electric bill then makes it seem like it's my fault. Our electric, water, and gas are about to be shut off and she has another two week trip planned in Aug. I don't know what to do, I have a 3 month old son to worry about and can't afford to move or pay what she has not paid. I just need some advice.

*****I can't go back to work until sep. Since I work at a work study position.