first of all... there is absolutely no reason to make things so complicated.
all these issues are things you'll have to work through, and hopefully you'll learn something in the process. i had a friend like your 9th grade friend... i never understood why he began to pick on me and make fun of me, but my 7th and 8th grade years were hell thanks to him. eventually i found enough strength within myself to not only make new friends, but that same guy ended up becoming one of my best high school friends. the point is that people that age are just too immature to be taken seriously... don't let them get to you because their opinion means nothing in the long run.
as for julia... your attraction to her is natural. she's probably one of the few girls who's shown you any attention and kindness in the past few years, so you latch onto that and begin planning your future with her in your mind... but she just wants to be friends. you've been through this with her before and it didn't work out... and yet you're going through the same pattern again.
to have any kind of lasting relationship (with any girl, not just julia) you need to work on your self esteem and build up some confidence... otherwise you'll just get walked on like a rug. julia seems like a great
friend and i bet she'd help you out with that if you asked her to.