Boyfriends mom so annoying!?

Ok so I have lived with my boyfriend at his parents house for about 3 years now. I am 21 and he is 19. Me and his mom used to be great friends I claimed her as a mom and she always called me her daughter. So anyway, for the past 6-8 months she has been the most awful person to deal with. I just got a new shift and she flipped and went nuts cause i came home to take a nap after work. She brought up how she used to work 2 jobs when she was young and dah dah...I mean what is the harm in me taking a nap? She keeps threatenting to throw us out if we dont do every little thing she says. She said i have to go to bed at a certain time and Im not allowed to go out after midnight...I pay rent and Im 21 mind you!! My boyfriend gets so freaked out when I talk about moving and I dont know what to do. I am so stressed and actually afraid to come home from work cause I have to do everything she says, if i dont she gets mad and theres no end to it. Then the next minute she will act like nothing happened and try to be nice. I need some advice please help!!