Renters rights??

I need help, for the safety and health of my child. This house was rented years ago, and it has ALWAYS had roaches. We've (combined effort of me, my fiancé, and his mother) spent hundreds of dollars trying to get rid of them, and it turns out all the houses down the road have them too, which are owned by the same landlord. They've seemed to just get worse and worse every year. If we had the money or the place to go, we would have left a LONG time ago. This house is disgusting, and unfinished. I cannot sleep because I hold my daughter all night to make sure nothing crawls on or touches her. She's two months old. The carpet in the living room is so disgusting, we found maggots in it the other day. The living room is nothing but drywall, and the kitchen is, UGH. I didn't personally rent this home with my fiancé, it's his mother's and we share the rent with her and his grandad. We've only lived here for three months. I didn't find out until recently the landlord could be responsible for getting rid of them, because they have always been here. Is there really something we can do? He knew they were here when he bought these houses. I don't mind paying to fix the stupid floor and finish the stupid living room, but we've been through hell and back trying to get rid of these disgusting creatures. I need advice or something, please. 😢