Why is my ex being mean to me, when she rejected me [10 points]?

[xBAKE12]

Okaaay, so this is going to be long, but it is unreal how much **** i am in, and how much help i need so please bear with me, because i would really appreciate it, plus you'll probably get 10 points from it

I asked my ex girlfriend out about a week ago, but it wasn't quite as stupid as it sounds. She became really close to me again before, gave me her new number, we started hanging out again (just me and her), and i kissed her (she liked me kissing her), she said so many things that hinted towards her liking me again it's unbelievable. I'm still shocked she said no (as cocky as it sounds), she practically asked me out. Anyway, she rejected me, i asked her if she wanted to try again because i still love her, to which she said "I don't know, bad time isn't it" then ran off. She didn't text/call or chat to me at all for the rest of the day.

I was so sure that i was going to get with her, that i thought i just surprised her or something, so i acted normal around her, and casually brought it up, she changed the subject straight away, not even saying anything to do with it.

I started getting the picture that i wasn't going to get with her now, so i talked to a friend about it and she told me that my ex was chatting to her and said she doesn't want to get back with me, so as usual i became depressed for the rest of the day, my ex texted me later on again though, only this time with no "x's".

A couple of days ago she started talking down and patronizing me, we would be in a group and she would take the piss out off everything i said, when i asked her if i upset her she would say "i'm just joking, don't get emotional", she's never acted like that towards me before. Later on that day i got into a huge argument with my parents and became really upset, so i put one of those attention seeking posts on twitter, my ex texted me and called me loads right after i posted it, at first she seemed like she wanted to help, but she got really pissed off with me for some reason at the end:

Me:
i feel like i piss every1 off, which is why every1 tlks dwn t me.

Her:
Wel do somin about it!!!! Other wise ur lettin them win !! Especialy depresin statuses bout urself that doesnt make people feel bad it makes em think wtf his prob!! Cmon mown ur just given em fuel!!!

Me:
i sed i didnt wna tlk bout it, sorry im bein borin

Her:
Wel **** off then in future wont bother but if u stoped makin ur situation sound worse then people may not take the piss so much an u would realise ur life aint so ****

Me:
well wt do u wnt me t say? im nt sayin my life is ****, im jst havin a tough time atm. jst gt into a huge argument wiv my parents, i realized today tht im doin **** at school, nd i piss people like u off all th time wen i dnt mean 2. so im jst nt in th best mood. im sorry, i didnt mean t annoy u. i feel like this is turnin into an argument nw tho, nd i hate tht. which is y i sed i dnt wna talk about it. thanks for askin tho, i appreciate it, nd u cheered me up a little

Me:
ill delete th tweet if its annoyin u?

She didn't reply, and the next day she pretty much ignored me, whenever i tried to talk to her she gave me this look and acts real cold to me. I can't even apologize. For the past three years i have been chasing her, we went out for only 2 months last year, she got me so depressed that i started cutting (last year), and even contemplated suicide. I don't get why she's acting harsh to me, when in her own words "i'm nothing but perfect to her", i'm the one who got rejected ffs.

I would ask her this instead of you on yahoo answers, but i can't even talk to her anymore, we haven't spoken in days, she was at a party last night, she got drunk and seeing the pictures i think she got with some other guy (which kills me).

I don't know what happened, this time last week i was 99.9% certain we were getting together, why does she always play me around? Is it true that girls don't like nice guys? I actually don't think i've ever said anything bad to her, but she constantly breaks my heart.

Thanks for reading this, i really need some help so anything you have to say, i'm desperate to hear, thanks.