Perhaps not a very good/descriptive title, but hey... turkey coma. Don't expect me to be eloquent right now. XD

Anywho, I'm confused about my relationship with my best friend/wife/secret lover/??? .

We've been friends for 5-6 years, and of late we've been just about inseperable. I've liked her the whole time. 2 years ago I took her out on a date and it went no where (she was dating someone else). A year later I made her a handmade plushie of her favorite game character (lol, we're such nerds... but she loves that thing so much) and told her how I really felt... and she rejected me. That's when things started getting really weird.

About a week later our friendship started becoming exponentially closer, to the point where we were called "husband and wife", tons of flirting but nothing further.
So about a year later, when I came back from a month long trip to Japan, she literally tackles me at her door and constantly tells me for days how horrible it was to be without me, etc. Mushy gushy stuff. XD

So I decide to make my move and confess my love (sounds so cheesy) after we get back from a trip to the beach (missed a great opertunity from atop a hill watching the sun set over the sea...).

When I tell her how I feel and ask her to be with me, she at first tells me she feels the same way and says yes. I'm happier than a pig in poo.
The next day she tells me she changed her mind. She says I'm the only guy for her, that she likes me alot, but that she doesn't want to be with me.

Since then she's started switching between being so close she'll actually make sexual advances (!) to being extremely cruel and vindictive, often within the space of a day. She has even called me "the Seme to her Uke." (Actually I'mthe uke of the relationship...lol).

What the hecks going on? Any ideas as to why she's doing this??

Sorry for the TL;DR, hadta vent...