P90x HELP! I am confused!!!?

Hi everyone I want to start the P90X soon, I have the DVD's and everything, but I have some questions. I've been working out for 7 months, running 3 miles 3-5 days a week and many squats and lunges, as well as pilates. I haven't gone to the gym in two weeks, but that is because of university midterms. Anyways, is this program for me, I really want to lose 15 pounds or more, maybe not that much but at least go down 2 sizes! I also want to know about the diet...it seems like they want me to eat a lot of protein, but I don't eat meat. Any alternatives or suggestions..I'm 5'5'' 125 pounds!