My mom is trapping me...?

My mom is a control freak. She has to have everything her way and I feel so trapped. I don't doubt that she loves me; I know she does, but she is always so uptight. I have my posters on my wall and they are very important to me. I accidentally got a makeup stain on her new towels so she took my favorite poster off of my door and shoved it in her closet. She said that if I permanently stained her towel, I can never have my poster back and if it comes out I get it back in a week. It's her punishment for everything and I hate it. Plus if she gives me a chore and I don't do it when and how she wants me to, she makes me do her dirty work. She wanted me to clean our kitchen--if it was that big of a deal she should have done it herself--and when I didn't do it immediately, she made me clean the kitty box. That may not seem so bad but it was her turn to do it and she hadn't done it-- the reason I know is that it clearly hadn't been cleaned for at least five days so she didn't do it when it was her turn and made me do it when she got pissed at me. She always snaps at me and makes me do stuff for her like get her drinks and let the dog out when I'm in my room and she's right next to the door, or saying turn the lights off when she's next to a switch. When I try to confront her she says that she does so much for me so I have no right to complain. I want legal emancipation but I have no money to take care of myself. I feel so trapped and I can't take it anymore. I have sensory issues and anxiety/stress along with all around authority issues. I don't know if I'm overreacting but I don't know what to do.