This friendship is getting to be too much...

Guest

I met this girl last summer, for now let's call her Jane. She and I have been best friends since. Since we go to the same school, it's easy to keep in touch and she lives right down the street, so I can visit her often. But lately we've been getting into fights. I've been suicidal for 10-11 months, and am currently seeing a therapist. "Jane" didn't know about this until last saturday when I told her I couldn't go to the mall with her because I had to get an evaluation and meet my therapist. She took it pretty hard, and I feel bad that I told her. But before she knew, we were best friends.
Up until about 3 weeks ago we had only fought once over a boy around November (it was a really stupid fight). Then we started to fight about everything. I apparently lacked proper social skills, which is easy to believe because the only friend I had for 6 years wasn't very popular, and she didn't really teach me anything about friendships. But "Jane" and I fought about how I assumed everything and how you're not supposed to wear your hair back with hoops and most recently about who's on american idol. And when I told her about my little black problem (as we called it in public), she totally flipped and started telling me that she couldn't live with me not being there and all of the love she'd put into waste in me and how I was planning to just leave her when we're about to graduate. To me, it sounds like we're lovers the way she put it (we're not. I've had a boyfriend for 4 years).
But lately she hasn't been as warm to me as she used to be, and she always seems to be on edge about everything, even when she's with her other friends. I don't know what to do about it. It seems like she's cranky at everything and everyone (even her boyfriend of 2 years) everyday.

What should I do about this?