I am now 22 and living on my own, and doing really well. I have come to the realization that my mother has always chosen my brother over me. I don't blame my brother at all, but I really want my mom to know how much she has hurt me and I want her to realize what she has done. How do I tell her all of this
Ask her if she wants to hear what you have to say. If she answers yes, you can start by telling her what you appreciate about her. Then you tell her about your feelings without blaming her. Finally you ask her to give you what you need from her.