My mom is making me too self conscious...?

So I am a 17 year old girl, 5'4 and 120lbs. I do a lot of dancing and am constantly out and about between school, work, dance, the barn, the dogs, etc. My sister is 19 and pretty much never home anymore, and I am the only other kid. My mom has been spending some more time home now that horse show season is over, so the barn people don't need her around for those and stuff. So, with her new energy and time, she has been constantly picking at me. Stuff that she has let me wear since I was born, like tank tops or even just my dance clothes, she sneers and says I am in my underwear and need to put clothes on. (Dance uniform is tights and a leotard, but outside of dance, I wear shorts or yoga pants and a tank top and/or jacket over it.) She gets nuts over it. Just the other day, she and I had to walk down the road together to get the other car to jumpstart one in a parking lot so it was like an hour long walk back to the house. She was teaching me to drive a stick shift up there and the car had been neglected for a few months as my dad is at sea... She flipped out on me when I walked on the road right next to the curb and made me walk in the grass where it was lumpy and folded in on itself and I pretty much almost sprained an ankle like 15 times during that walk. She knows for a fact that I have been on hundreds of walks by myself or with my dog and do NOT walk in front of cars, nor on the lumpy grass. She wondered why I was frustrated and I told her this, but she didn't care. She knows I take my bike everywhere and walk everywhere and has no problem... She even makes me walk down to the gas station to get her an ice cream when it is dark out! Plus, she has started trying to make me go on a diet and getting mad when I eat something she herself will eat- I am a vegetarian. She is not, but accepts my choice. I have been for over a year and am perfectly healthy. I also work at night time, usually Fridays to Sundays. I like to go in an hour early to eat, but my sister was being slow so I decided to grab a piece of pie while I waited in case she was dawdling too long. My mom pretty much flipped out on me and she gets mad whenever I am not eating an apple or something. Yesterday, I got Subway after school, so it was around 3:30. She got home and wondered if I wanted pizza. I said sure and then she saw my subway bag in the trash and said I didn't need anymore food. Seriously? I had dance that night. Subway was my lunch because there is nothing at my school I can eat. She has NEVER been this way, but suddenly she is all over me. I know she was picked on in her family as a kid and lots of other bad things have happened to her, but she has always been fair. I am suddenly being treated like a six year old who does not know how to walk in the road, can't control what I eat, and apparently don't know how to dress. She even accused me of being pregnant a few months ago, even though she knew as well as I do that that is not possible and that I am not stupid. There is no talking with her for many reasons. I'd rather not get into that, but we will say she does not listen to be simple. Oh, and she is always threatening to get rid of my cats or questioning how I am caring for my fish even though she knows nothing about them, etc. I seriously am going to move out next year when I am 18 if she doesn't treat me my own age. Don't know how I will do it, but I will find a way. How can I deal with her and try to get her to treat me my age? This is not cool and I am not used to it, nor do I accept it. I have gone pretty much without parental guidance since I was 11 because both of my parents were working too much, now she is trying to slather me in it like butter, and going about it the wrong way. Advise?