Should i break up with my girlfriend?

She loves me a lot and tells me every day, but lately she started acting weird. She get mad and frustrated easily and for no reason. Like today she got mad that she wasted 50 cents on cookies she didn't like. Who gets mad over that??? Sometimes I think she is using me to.....she gets upset and ask me to do something and stays sad until I do it. I'm also moving this summer too, and also I've been flirting with these girls a church( I'm ). Every time I mention breaking up she starts crying. Wht do I do????