Hi nimPy
I think you may need to give her an opportunity to improve before breaking up with her. I think you need to seat down with her and get everything out in the the open and onto the table. If she does not want to open up and does not explain why she is acting so cold and reverts to her ussual methods then you have to make it very CLEAR to her that this relationship will end.
My ex used to act in this way and it really drove me insane. She did it more selfishly though. She wouldn't tell me what the problem was and say something like you have to KNOW yourself what it is i am unhappy about at any given point in time (I did not know i was qualified for a mind reading position). In any case i think you have to give her a chance to improve and to understand the severity of the situation if she doesn't. Breaking up in the heat of the moment really doesn't help much and only adds to the weight of the problem.
Hope above helps!!!
Don't cry, don't regret and don't blame
Weak find the whip, willing find freedom
Towards the sun, carry your name
In warm hands you are given
Ask the wind for the way
Uncertainty's gone, your path will unravel
Accept all as it is and do not blame
God or the Devil
~Born to Live - Mavrik~