Why is my coach acting like this toward me?

I have been twirling for 6 years. i join this new group 2 years ago. my old coach started up a new group. She gets on me about every little thing i do. i practice every day for 1 hour. there are 2 other girls on the same level with me. it is only 3 of us. the first girl has an attitude problem she gets mad when she is not put in the front,but she doesn't have the Technic,the coach even said that. the other girl never really comes to parades or practice. We did a parade 4 months ago and me and the other girl had to lead the parade. of course she had a attitude the whole time. i call out everything routine we had every learn so the other girls could follow after. when it was her turn she did the same 8 count over and over again. I remember in this parade that i was told i would be put in the back for not doing my part. After this parade she was telling me i should try to be more of a leader, but doing the Holiday break I lead over 20 girls down the street by myself in a christmas parade. Why is she being hard me and not the 2 other girls. I have been twirling for 6 years and has done competition's. the 2 other girls have been twirling for only 2 years. also the coaches say i am in a box whatever that is.i guess,because i keep to myself at times,but i am not shy i interact with everyone on the team. I do not know what i should do. should i leave or stay and stick it out. i want advice from everybody.