How do I get along better with my mom? This is serious...?

Hello i want to know how to get along better with my mother. ok so you may have seen my other posts but i have developmental delays and i am in 11th grade. my mother does not take me seriously AT ALL. my mother constantly argues with me about stuff, my mother constantly interrupts me and answers for me. my mother does not trust me to do anything by myself. my mother is way too overprotective of me and does not let me have any freedom even though i am a young adult. i tell my mom to give me some space but all she does is argue CONSTANTLY with me and i cannot take another minute of it. we are seeing a therapist but it isnt helping as much as i want it to. i am homeschooled and my mother always tries to help me with EVERYTHING even though i have a tutor. my mother has good intentions but cannot stop helping me and doing things for me. my mother argues constantly with me about stupid stuff. if i mention that i am going to make myself a snack my mom will insist that she make it for me to save me the trouble. she will argue with me till i finally give in. I WANT MY MOTHER TO SHUT THE HELL UP FOR GOD'S SAKE! most people say i am the most mellow guy they've ever seen but i cannot take my mother any longer. my dream is to run away to new zealand and live on the beach. my mom cries every time i say im gonna run away. how do we speed up us getting better and help my mom take me seriously? i am so freakin sick of her to the point where i don't want to live anymore. i am so confused... there is such a thing as being OVER helpful. no matter what im doing like if im trying to clean my desk or room, my mother will immediately start arguing and insist that she do it so i do not get tired. I have a heart condition and my mother is WAY TOO FREAKIN PROTECTIVE! my mother does not let me eat fast food because she is afraid i will get a heart attack. I JUST WANT TO GO TO FREAKIN SUBWAY WITH MY FREAKIN FRIENDS! My mother makes me wear a sweater or jacket to go outside because shes afraid i will catch cold. I'm 18 years old im not a baby. My mother argues with me and is way too freaking over protective. My mom does not let me do things i wanna do like learn how to make chicken for dinner or go somewhere by myself or stay home alone. my mother is very afraid for me and homeschooled me because she was afraid public school would be too scary for me. I want to go to public school but my mother fears for me. I tell my mother not to help because she's making me hate her but she does not take me seriously. I tell my mom i dont love her but she just cries and tries to help even more. my dream is to move out but i do not know how to do that. i cant drive and i dont work so who will pay for all my medication and how will i get groceries. my mom does not know how to shut up or when to stop talking. All i want is for my mother to shut her trap and let me be more independent. I want to run away so bad