My friend always gets the lead role!?

Me and my best friend Katie have loved acting since kindergarten. We would play the soundtrack to a show like Little Shop of Horrors, Greece, Seussical, or Bat Boy and make our own little production. We wrote our own plays and performed them for our parents, had so much fun. We decided from the first day that we started doing this that we would be leads together in all the middle school plays and that it was going to be great. During elementary school we would both audition for student films at the local college and Katie would usually get the parts because she was smaller. I am freakishly tall, and was about the same size as the college students, so I never got any parts. Oh, and her dad is also the head of the theater department at the college. So I thought that this would change in middle school and we would both get lead roles. Then middle school came, and we auditioned for the first show together (High School Musical). She got a callback and I didn't. I was a bit upset but I still felt happy for my friend. She got the role of Kelsey and I was ensemble. I though "Oh, its the first show and she has a bit more experience, it will be better next year). Well in seventh grade we auditioned for the show (Annie) and we both got callbacks. She got a callback for Annie and Lily St. Regis, while I only got a callback for one of the orphans. In the end, I got the role of Duffy, and she got the role of Annie. I was still upset about this, but I was still fine with it because I got a lead role. Now THIS YEAR, we both auditioned for Beauty and the Beast, and we both got callbacks, I got called back for Mrs. Potts and Madame de la Grande Bouche, while she got called back for those two AND Belle, Babette, Le Fou, and Cogsworth. She ended up getting cast as Belle, while I got cast as a featured towns-person and a plate. This is where I got really annoyed and started feeling a lot less happy for my friend. For our spring show, instead of a play, we are doing a revue of all the shows that our school did in the past 6 years. I was so excited because it was finally my chance to get a good part, and it turns out that Katie got THREE solos. She gets to be the Cat in the Hat for "Oh the Thinks you can Think", she gets to be Gertrude for "Notice Me Horton", and she gets to be Belle for "Home". Then I see what song I have, and I have a SEVEN measure solo in "You're Never Fully Dressed Without a Smile". I was really upset. I always had thought that me and Katie would have the lead roles together, and it just turns out that she is better than me and will always have a better part than me. Now she has been in several shows at the college, the lead in every school play, the lead in several of the local theater company plays, and she even has an agent. I really am sick of being in her shadow all the time. We were best friends, but now I am always jealous of her. What should I do? I need help! How can I get the lead role if she has so much experience? Please, any suggestions will help!