Shes Always Fighting With Me

Okay, so me and my girlfriend have been dating for a year in a half. We're both in high school and in love etc etc.

but now for the past who knows how long
she constantly argues and fights with me

over the stupidest thing and she always has to have it her way!

for example, we both have a facebook(its similar to myspace)
and we both use it etc etc
so recently i had a picture of us and i changed it to this other picture that shes not in and she flipped out on me and said that was wrong...


funny thing is, her picture doesnt have me in it!
I also told her in a text that she can never control me or anything like that because i feel like she tries too, though she'll never admit to it and always say she doesnt.... i just strongly feel it.
and now shes gone all day without talking to me.
she also complains when a picture of her is not on my phone wallpaper etc etc
stupid things and i feel like shes also trying to control me because she constantly brings up past events when I'm not doing something she likes

she also has insane jealous problems and gets jealous of this girl that i'm friends with. (girl is a freshmen.... i'm a senior....)
she also likes to say things that threaten me and the relationship as in "we're over" and things like that when she doesnt get it her way and she doesnt see how much that hurts my feelings or anything...

shes so fixed on what she feels that she doesnt see that i'm slowly losing everything i have for her because of how shes been....

she also has these mood swings lately....
she'll go from really happy to really mad and anger at me in a snap....


what should i do and was me changing my picture and saying that she can never control me really that bad that she goes all day without talking to me?