Im Bi, and losing a best friend, HELP?

So my freind (girl), thinks that we need a breather because my personality is apperantly annoying, but i act just as anyone does at our school, I even asked all my other freinds and they say I havn't done anything wrong at all. So she says she wants a breather before she thinks one of us is going to snap. Now I am an easygoing person, and i love to make freinds and nobody ever seems to have a problem with me other than her, and she does seem to have these mood swings and all but everyone who hangs around her just ignores them, also I apologize alot to her which I think I don't have to, and either do my friends because I never do anything wrong she just takes everything to personally, so before our freindship is on the brink of disaster can anyone help!? shes one of my best freinds and I don't want it to end (I'm 15, shes 15, and were both girls) and another thing, I'm Bi and we have kissed before, shes confuzed about her uality, there also has been turmoil in the past where she hasnt even talked to me for a month because of a kiss (even though she did it), I don't like my freind anymore than a freind, and there also has been a part where we were never freinds before and hated each other but now it's two years later and thats in the past, do you think that could have some part in it aswell?