My oldest son

Hello my name is Eileen and I am new here.  I would like some advice if anyone can give some?
I have two sons one is 27 the other is 22.  I moved here to Calif be with my oldest boy, grandson who is almost two and my sons girlfriend.  My other son is in Washington State which is our home and he and his girlfriend are having a baby in June.  My youngest wants to move back home hes just a real sweetheart of a guy.  

This is my problem my 27 year old wanted me to be with them and I have watched the baby many times sometimes until 4 in the morning while they were out.  I do live with them now and being that Calif is so overpriced I can't afford to live on my own and I do pay them rent money, help with the baby and clean the house.  His girlfriend doesn't lift a finger to help around the house she is lazy and a slob.  My son goes to work and when he gets home has (as he sees) he has to take care of the baby and clean up after her, make dinner etc and so it goes day in and day out.  He treats me like I am a second class person, meaning that he pretty much doesn't want anything to do with me.  I spend almost all the time after work in my room as to give them their personal space as much as possible.  I know that they need their own place and have told them so many times.  He says very hurtful things to me like I don't care if your here or not it doens't matter to me.  One time I was crying without making any noise so he didn't know and when I answered the door he asked what was wrong, when I told him that I felt like I shouldn't have come he said that your acting like my uncle and it's stupid to cry so why don't you just go home.  I should also say that her mother lives here too she has the big room with a walk in closet and full bathroom, her daughter is just awful to her says mean things to her all the time daily.  We both know we need to not be with them but the bady gets mixed up in all this and he doesn't get what he needs so we try to help him.  It gets much worse then what this sounds and we are both worried for the baby.  I have made the decision to move home and continue my life up there, she never wants to live in Spokane because she says it dirty and the roads are just not the right shape what!!!!!! Not the right shape?  Oh well please let me know.

Thanks so much for reading.