Losing my mind

So I had to move out my apartment in January because it was only me and my 2 kids there and rent got to high for me to afford on my own (along with my other bills) not to mention my AC had been acting up for months and no one ever came to fix it and when you called the office no one ever answered and I was over it! Well I moved in with my mom for the time being and I'm seriously regretting it. I'm miserable there. My sisters 2 kids live there as well (my sister basically lives with her bf so my mom takes care of her kid's 90% of the time.. Long story) well I thought my sister was going to be moving out with her kids but has yet to do so so I sleep on a day bed in the living room, my 7 year old sleeps with my nephew in one bedroom, my mom and niece sleep in the other room and my 2 year old sleeps in a crib in the living room with me and now I'm pregnant (I'm 18 weeks) and I'm so stressed.. My mom is constantly complaining about something. I told my bf I didn't want to live there and that is why. I don't get along with my mother when I'm living with her but my bfs place is smaller then hers and unfortunately we just don't have the funds to get a place together right now and I had to quit my full time job bc of my health (I have heart issues).. My car got totalled in an accident last month thanks to a red light runner and I was going to use it for some extra cash (I work from home) l understand where she is coming from but I can't handle listening to it all the time. She won't tell my sister to take her kids because my sister pays half the mortgage (I pay the other half) and she's afraid my sister will stop paying it all together so instead she just complains to me about it. I'm so stressed out! The housing market is horrible where I live (2 bedroom places are like $1200-$1400 a month and buying is even more expensive) I honestly just want to buy an RV and live in it with my kids. I just want out of that house! Sorry I just needed to vent bc I'm losing my mind!