Is It Me Or The the Situation?

Okay...So My husband and I have been going thru a rough patch. We have been arguing a lot lately and I'm feeling a bit unsure of the source of or problem therfore I'm not sure how to solve it. It could be us and we need to seperate or it could be our current situatuion. Now the situation is we have been staying with his sister who is married and has four kids oh and a dog. We are staying there becuase until recently we only had one income. I've been so fustredted lately beuase of a few things. The kids can be annoying with all their questions and being a bit loud and sloppy but that I can take. It's a bit croweded and everyone is very nosey about our business and That I can take. What I cant take is the mood swings and comments that come from his sister. Okay so she can be very insulting at times but she thinks she can get a p because she say's it jokingly. Like for instance she will insult my intelligance if I don't understnd one of her dumb questions by saying Im a little slow. Then she'll say I'm anti social becuase I don't like big crowds and I tend to avoid them so I won't go to certain events or places with her. I work in Customer service for goodness sake!!! Then she'll jokingly make accustions that I cheated on her brother because our 2 kids are a lighter complexion than him. She call my daughter ming and says her real dad is aisan. arrggghhhh!!! Then she insults me of course jokingly by saying that im turning my husband against his family becuase I never had one. Now Im a bit of a loner but I care deeply for my kids and my husband and to her this is bad. To her I have to care about his entire family so If I buy a sandwich, I need to buy the whole dang family one or else I dont care. WTH!!!! And Finally when I'm in a bad mood becuase of this increasingly annoying atmosphere she will say I'm BI Polar. Gosh So I talk to my husband and he say's don't worry we just gotta find a place. Okay fine but then she will tell him Im rushing and we sould wait until we are stable. Now this is riduculous becuase I know whe wants us out but she does benefit becuase we fill up the fridge and freezer and give her cash. When i come home from work Im just in a general bad mood and every thing my kids or husband do or say seem to just really get on my nerves especially my husband becuase his mood will be kinda down too. With us bickering so much and the arguments getting more heated, I'm wondering when we finally do move out shoud it be into two different homes???