What you guys think:

On twitter... I was jokingly flirting with a woman i didn't know -- I watched one of her videos and decided to tweet some flirty things to her (knowing she wasn't going to reply)

My GF's friend (from what i heard) told my GF about this and told her to break up with me

So me and my GF were talking before i got to work at 12pm (EVERYTHING WAS FINE!) ... So i msged her after work and BAM! She goes cold... after a few lines she says "I don't want this anymore"

I talked to her today (Saturday) and she says I've said/done a lot of stupid things during our time together and she's fed up with it (and this whole twitter incident was the tip of the iceberg lol)

So after talking and talking (this was on Wensday) on Saturday .... I told her I'm willing to compromise but she says she doesn't know if she can just jump back into things .... So at the end of it I said: "if you don't want to work things out then: thanks for everything it was was fun and i learned a lot " (being the positive person I am)

I was wondering -- did she lose attraction? Or is she just overreacting?

So at the end of it I said: "if you don't want to work things out then: thanks for everything it was was fun and i learned a lot " (being the positive person I am)

I like the way you handled it, *thumbs up*.
However, you got caught flirting and now have to deal with the back lash.
You can't blame the girl for being upset, you hurt her feelings.
On the other hand, you can't spend every waking moment saying you're sorry either. You screwed up, you are only human...if she is not ready to forgive and forget so be it.

_________________
Keep people off-balance and in the dark by never revealing the purpose behind your actions. - Robert Greene

Also
The better you take the break Up
The better your chances are of getting back together with her

In the end girls don't know what they want
Attraction isn't a choice
Maturaty is shown in the most critical moments
Maturity is attractive when most guys would get angry and confused
You show complete self control
Good job

You dont mention saying you were sorry. You did wrong, you should feel sorry and you should say it.

However you have handled it well, as well as you could have done. Like the others have said being mature about it where most wouldnt is attractive.