I Wanna Go Back Home

I have not been active on here for months, so a lot has changed. I got into a fight with my stepmom, my dad kicked me out, and I'm now living with my bio mom and attending public school. Yay.
Now don't get me wrong, I love it here with my mom but I'm shut off from everything. And depressed. I'm having a lot more break downs than I had six months ago. My mother won't accept that I'm trans or she either tries to ignore it. I can never talk about it because she doesn't understand. It would be fine and all, but I have NOOOO support system out here except a few people. Other people joke, laugh, point out my birth name, call me a girl, and shove it in my face. Sometimes I just cry when I get home in the shower. The fact that I can't even go to a school restroom makes me upset enough because I can't even use the restroom I want to. It kills me. I feel so alone...I don't know how to deal. Part of me wishes I was still at my dad's house. I hate here sometimes. Sure, my dad didn't accept it either but he never had certain standards for me. I miss hearing just my little brothers and sisters say "my big brother". I know I made a mistake and took for granted what my dad had offered me. I think I get what he was trying to do when he sent me here at the beginning of the summer. To see what I took for granted, and I see that now. We didn't have a perfect relationship, but I miss home. Home where my siblings and family is...I get that now....I wish I would have seen it before I decided I wanted to live with my mom. She files custody the beginning of next month! I need to tell her before she does, and I need to apologize to my dad and my stepmom. And my sister, who got so depressed because I wasn't there and tried to kill herself. That hurts me that my sister felt so alone and I just left her.
I saw all my family for Thanksgiving at my dad's and I could have fit into my old life so easily. My little brother cried when I left and that left me heartbroken. I wish I had stayed....now I've got to find a way to tell my mom that I want to go back....such bad timing....christmas is coming up...how am I suppose to tell her??
I just hope it isn't too late for me to go back. I'm gunna talk to my dad before my mom to see if he'll forgive me. My mom may be mad about it, but that's her problem. Not mine.
Any tips?