polygamist relationship

I am in a polygamist relationship my husband has two wives. I have been with him for 9 years we have two children and I on the way. My relationship with my sister wife is not so good. I feel she is controlling and only in this relationship for the help. She is only happy with me if I'm going down to her house and cleaning and cooking for her. I feel like I'm the one on the side because the husband is always down helping her. I live in a tiny house close to hers and he hardly comes up to say hi or anything unless he is leaving to be gone all day he is here to sleep 3 times a week but most of the time it's not tell 9 to 10 at night and then leaves at 4 am to take son to work and the nights he is not here he spends 30 minutes with us. He hardly calls or anything. He says he loves me and loving when he is around us but I almost think it's for show what do you guys think. I have no family close by to go to to leave nor do I have enough to move to where my family can help me.