Sick of the way I’m treated by family…

I’m at my wits end with my mom… I’m 25 with a 3.5 year old, and have been living here for a little under a year ever since my son’s father and i split. The “plan” was 6 months here, then I’d buy a house in the spring. There’s been absolutely no decent houses available in my price range, so that fell through. She is constantly nit picking every single thing i do. In regards to my parenting, myself, everything. I clean up after him and i, pay her, and buy our own groceries. I do whatever she asks me to do to help out, whenever she asks. We were always really close before i moved back in, and i just have a feeling once i am finally able to leave, we won’t have a relationship at all. I can’t be upset over ANYTHING without her having negative comments, and then she gets mad that i “don’t trust her enough to tell her things”. She’s constantly saying I’m too hard on my son, then I’m too lenient. Her and my step dad have spoiled him horribly, he doesn’t listen to me at all when we’re around them. I’ve tried telling her how i feel, but she turns it back around on me. I have a 19 year old brother that lives here too and gets away with absolutely EVERYTHING. I respect “her rules”, and yet I’m still treated like a teenager. My only shot at moving out right now would be to move back in with my son’s dad, and sadly I’m highly considering it…