Desperate need for advice.

So me and my husband are buying a house in July. His mom is going to move in with us later this year because she's loosing her house and car. Because she's trying to get disability and they are taking forever to get back with her. So her, her boyfriend, and 2 dogs are moving in with us and it's me and him plus 3 cats. And WE are buying the house but they are moving 5 hours to live with us since she can't work. (Severe back problems). I'm getting stressed on the whole situation. We haven't had to best relationship (me and my MIL) and I don't even know her boyfriend I've met him one time. And they been together for a long time. Well me and him have been together 4 years and married for 3. We shouldn't have to take in them but he don't let his mom live on streets which I understand but come on her boyfriend and her dogs too. I'm beyond stressed. She would move into her mom and dads but the boyfriend couldn't move in there. (I'm not racist) but I guess they are and she is Caucasian and he's black which shouldn't matter and she won't give her dogs up to live with her parents. What do y'all think about the situation? Advice is needed badly.