How do i get my mother to understand I'm grown up!!!?

hello everyone i need some help on this i feel my mom going to trap me in this house forever..I'm 24 years old i still live my mom and no matter what i do for her it's not enough i try and help her around the house and say's i do it the wrong way i can't do nothing right in her eyes she has O.C.D and depressen andi think she bipolar ...she always hitting me up for money she never leaves me and my boyfriend alone..she call's me names .. and then says well i can do it but you can't to me .. and right now I'm trying to save me for car but she sucking me dry for money and when i don't give her money she calls me names and crys where going to be homeless if you don't I'm trying so hard to help . but i want justed a little to save money and make her happy at the same time but i also want her off my back!!.. and top of it she hates me cause i can't fly or something to finish my g.e.d and go to college i just feel trapped sorry if this long... but i need advice and help on this i can't take living with her anymore i want my own life