i feel worse after coming out...trans problems

so, a few days ago i told my grandma that i like girls and that i dont feel like a girl. i went to a therapist yesterday and that was wonderful, but after telling my grandma, i feel like crap. i know she is disappointed. she keeps telling me that she loves me and the therapist said that she is handling it really well, but everything is so awkward and strained right now. she wont accept my gender problems/confusion or my chest dysphoria. she doesnt want me to get a binder and bind, although i sort of already am. but i still desperately need a real binder. the dysphoria is getting worse. i dont know how to help her understand what im going through. i never showed any questioning of my gender as a child and growing up, so i guess she just cant believe it. i dont know if telling her things that happened or things i did when i was little would help any. she only pictures her little dress wearing doll carrying girl. i had/experienced major problems growing up but never expressed them. i wanted to stand and pee (i would pretend that i could), i didnt want to put female on a form in 2nd grade. i loved wearing a pair of boys pants that i tried on for my cousin at age 9, i wished i could wear a towel around my waist like a boy (this was after puberty), i loved a pair of pj pants that could open in the front... it thought it was so cool. also i fought with her to not wear a bra. i literally cried when i had to wear one. so, i dont know if i should tell her any of this, or if it would make her resist all the more