!!!!!!! I JUST TOLD MY MOM!!!!!!!?

Ok, so im fifteen live with my mom in Arizona, i just came out to her and she reacted strangely. She seemed ok with it but not happy about it, she told me not to decide anything until im an adult, but im positive that im gay. Her argument is that im just confused and that my hormones are playing tricks on me. She says that its an epidemic because there is so many people coming out, i told her its because they feel more accepted but she doesn't understand. I have a lot of friends at school that know, and my brother was one of the first I told, so i have a lot of support behind me. I just am really trying to get her to understand what im going through, and i really really want her to just understand that i know im gay, i just want her to accept it. She divorced my dad almost two years ago, she wasn't happy with him. Two or three months after, my dad found out from my half sister that my brother was bi. Lets just say he wasn't thrilled. and now whenever im with him he tells me how disappointed he is with my brother. And he thinks that ity is a sickness.I really don't think i can tell him and still maintain a relationship with him. if there are any of you out there with any arguments that i could have with her to make her see that i cant change this, and that it is a normal thing. any help would be greatly appreciated.