Okay I am going to be as honest as I can be with this.

When it comes to breaking up with girls I have no balls what-so-ever.

I don't want to hurt the girls feelings.
wish i could give you some great advice or something, but yeah, i prety much suffer from the same thing.

i can tell you, more than likely (especially because you say she bases everything on you) she's going to cry for days, there is no easy way... but atleast be somewhat of a decent person about it, do it in person... i'm sure it'll hurt more if you do it over the phone, email or through a note in school or something.... be honest with her too... tell her you want to move on, that things aren't working for you... bout all i can say.