Because she wanted to change the relationship on Facebook and then I went off at her becoz I thought she wanted to break up with me :( but she didn't her cousin wanted to guess who her boyfriend was and now she is pissed at me because I had a full on go at her and now I feel like a idiot she says she forgave me but I don't believe her because she is still pissed off I don't know how to tell her I love her so much and if I lose her I don't know what ill do :( *** help

So by her changing her relationship status on Facebook is what started all of this? I just want to make sure I read this right.

Yes becoz her older cousin wanted to find out who her new boyfriend was she said she would change it to single and then she changed her message thing on Facebook and I was like so your taking me out of your life slowly?? And she got hell pissed then I said sorry and all this stuff and we were going to be OK :)
But then I told my friend (that's a girl) what happened and she said she would talk to her and I beged her not to but she did it anyway and that made my girlfriend more made :(

Out of curiosity, how old are you? I wouldn't read too much into it, it looks like just some harmless fun. I think the bigger issue is that your friend went and talked to your girlfriend (even though you didn't want her to), which probably made her feel like you were talking behind her back.

If nothing else, I'd be careful who you talk to about your relationship. Some friends will simply listen to you and provide you with a great set of ears, and others will try to take matters into their own hands.

Can you control yourself long enough for her to get over her anger?

Then you can talk.

It also helps to keep others out of your business.