Confusing Relationship with Friend

This isn't romantic in anyway, I just don't know where this kind of post would go. Anyway, on with the story.
I have a friend and sometimes I think I love her, and sometimes I hate her so much I wish she'd go and get hurt, physically, emotionally, I don't know. Just so she suffers.

We've been mostly best friends for 8 years and I've always had these feelings. We don't have that many things in common but we were best friends til about two years ago. We played loads of fun games when we were younger and we've had those serious girl talks and lots of sleepovers etc. and we have so much fun it's crazy and I laugh like never before.

And then it's like there's a black cloud. She's really selfish in the way that when she asks me to come over to her house, if I refuse, she'll get really mad at me, ignore me for a few days til someone makes her apologize. But then when we're not speaking, I'm not that bothered. I used to get so annoyed I wished I wasn't her best friend. Also she said I wasn't depressed because I seemed all chirpy and cheerful, that really stung. And whenever someone mentions depression she gets all attention-seeking talking about her depression and how horrible life was. She cut herself and then wore her sleeves up and showed everyone to make sure everyone knew she was depressed. That just got me so angry. I know that's terrible of me, and she does have some problems, but it's just the attention-seekingness of it all. Sometimes I wonder if she has a condition that means she's constantly seeking attention. I know that I can be attention seeking sometimes, but I really try not to be. I think "Could this be considered attention seeking?" and then I just stop whatever I'm doing. Right now, writing this, I feel like I'm attention seeking, but I'm trying not to be!

Okay, anyway, so most of the time she annoys me. And then I said I didn't want to be best friends and it was great! She got a new best friend and they fell out all the time and I was just the comforter which was great. But then she muscled her way back into best-friendship even though I have a different best friend and started to get irked whenever I tell my best friend he's my best friend. That's confusing.

Another part to this is that she used to be really shy, shyer than even me, but then she got different friends and started going to drama clubs and stuff and she got lots more confidence which also annoyed me, because I always felt like the stronger of us. She gets invited to parties of people we're both friends with and I'm just left out of it all. She even has the audacity to say she gets left out of it all! That's really mean of me, but it's just so annoying.

Then she's not supportive at all, when my first love started to go out with the person I wished was my best friend, she was just like "Oh well it didn't happen to me so he's still my friend and I'm not going to treat him differently" (as was most of my friends actually, if not all). And she constantly flirts with him (yes, she likes him too now and pretends that she doesn't when she flirts with him before my eyes, which just hurts my heart) and is "married" to him on facebook.
So yeah, sometimes she's alright tolerable, then she's just the person I hate most in the world and want to shoot. That might be a bit of an exaggeration, but not that much. I wonder if this disliking is irrational, or are those reasons valid to dislike a person? Perhaps I'll talk about this with my psychologist.

I know she's got some problems too, but when I'm spiralling into hell and she's flirting about and ignoring me, it seems like nothing at all.
Anyway, sorry for the long post and it's okay if there's no replies, because at least I got this off my chest! It takes up a lot of my time. Phew.
Also, I'm sorry if this sounds really petty and childish.

Sorry, I got a bit confused about whose who.....but the basics are about friendships.

Some people that we grow up with & are friends with....we tend to grow away from as we find we have less in common or we find we don't care for the way their personalities are developing. It's important to be friends with people that you like as the bottom line. Every relationship will have it's ups & down's.....that's just life when different people get together as friends......even at my age of 58, one has misunderstandings at times....but working through some differences is a growing process & can grow friendships closer rather than ending them. From what you have written, I'm really not sure that the girl who was your best friend for 8 years is really a good person to be friends with.....I think personally from what you have talked about & the way she acts around others.....I would keep my distance.

I think your idea of talking about this with your psychologist is a very good idea......sure your psychologist can get into some deeper interpersonal skill issues with you in this area & maybe give you some valuable support that you can take on into more relationships throughout your life.

Glad you are here & posting at PC.....I am sure others will have more input on your thread here....just hang in there & keep posting.