living with dad

So just a couple months ago I moved in with my dad, which may be all fun and dandy if it wasn't for his girlfriend, mostly we get along, but she is semi OCD, and wants me to keep up with her perfect standards, and I try I really do, but with all my physical disadvantages it's hard. She wants the bathroom to be spotless and on top of being a germaphobe I also can't physically put to much power into it otherwise I end up over using my body and that's it for me for the day, 15 minutes cleaning the bathroom and I can't do anything else. So we constantly have moments where we butt heads, and it's hard because personally, I don't think we should be having problems, I do everything she asks, and I do it to the best of my physical ability, and yet I'm still not good enough for her, and my dad has already told me if me and her have a dispute, it doesn't matter if she's right or wrong he will be on her side, which is hard, because I'm his daughter and he's already chosen someone else over me, himself, and now he's gonna chose her over me as well. I guess as a girl I'm supposed to look up to my daddy, for protection, guidance and everything else daddies are supposed to do, but I can't and then I don't even have a mom to look towards for help. What am I supposed to do when the 2 people in my life that are supposed to protect me and teach me aren't there to do it. Sure I can always move back in with my grandparents, and sure that was better for me in some ways, but at the same time it was just as hard, I had to be there for every medical scare, and see my grandmom's fear and pain, and have no way of helping, there's nothing I can do and it's hard, when the people who have taken care of me for my whole life can't anymore. I can see my grandpa slowly losing grip on his mind, barely able to grasp the easiest of concepts that used to be easy for him, and grandmom watching the man she loves wilt away, and all I can do is watch and hope they will still be around next week to take care of me. I guess I thought moving in with my dad my help with the stress, but I didn't expect for my dad to be just as stressful, sure it's in a different way, but it's just as bad. Living with the grandparents I wasn't sure if next week they would be around to keep the place I was staying and with my dad I don't know if his girlfriend will still let me live here next week. What do I do when I feel like there is no place for me to go...