I came out to my mom please help me?

okay so my name is becca i am 19 years old i am biual i have been for 5 years now. please don't judge about a month ago i came out to my mom she was okay with it at first but then she flipped out on me and was like i bet this is just something you will grow out of it and its prob the new fab. when she said that it killed me it took a long time and guts to come out to her she acts like im not gay and when i bring a girlfriend home she sends them home and its not fair. i don't know why she is treating me so differently i thought she would support me in this she supports everything else that i do i just don't know why she wont accept the fact that im . its who i am i was tired of hiding it and she made me feel like crap. i hate when she acts like im not bi . it doesn't change anything about me . all my friend support the fact that im bi . there are groups for teens and parents for gays biual and trans but she wont let me go to the meetings i think it would be good for her to go and get information . instead of shutting it out completely my bro isn't to happy that im bi but he doesn't treat me differently. i feel like i made a mistake on coming out to her. my dad knows i thought he was going to be the one who would pretend that i am Straight but he supports is surprisingly. it just hurts allot i thought i could trust my mom but i guess i cant . please some one give me answer on what i should do, because im at the point where im ready to kill myself because i cant take the fact that she wont accept me for who i am. did this happen to anyone else if so please help, i need answers fast thanks