Help!! Mother in law and newborn baby

Firstly me and my husband live with his mother and father and he currently has his little sister (21) living at home. We are trying to get our money together to get a place of our own, but he’s the only one working and we just had a new born baby. Since being home from the hospital with the baby his family is driving me insane. I’m starting to not want to ever leave the room me and my husband share. I told his mother I don’t want my baby sleeping on his side that I would like for my son to be slept on his back. I had gotten admitted into the hospital for health issues after having my baby. Anyways So when I was admitted to the hospital she took it upon herself to sleep my baby on his side after I told her that I wanted him on his back. I told her I don’t want anyone kissing my babys face and she still does it. I’ve told her over and over that I don’t want anyone’s lips near her face that the feet are fine to be kissed. His sister gave us attitude about it and said she will do what she wants and still kisses his face. His sister has mouth herpes and I don’t want that near him! When I went to shower she came to the room and took my baby I got out of the shower and my baby was gone. I left the baby alone for 10 minutes so I could shower... I had a monitor that I take with me so I can hear my baby. I went to find my son and my mother in law was holding him on the couch. I asked for my son back and she told me to give her a few. Every choice I make for my son she always says I’m doing it wrong I need to do it her way. What can I do :( I’m so over it and it’s ruining my marriage. She never listens to me. I’ve tried talking to her.