Yeah, I'm going to have side with shheadz on this one (as if there would be any other way!?).
Just by reading your posts, and based on everything I read and everything I've experienced, I can't say that I trust in this miraculous and fast transformation. Like shh has said, there have been so many people that have been at the stage you are at and say the things that you have said. I was one of them. But you are in panic mode. You have lost something that is important to you and you are feeding your selfish inner ego trying to get back what you had before.
You have been apologizing since the break up began and as you said you have been justifying yourself. Even in your other thread, I read how you didn't cheat on her and did all these great things. Don't try to feel sorry for yourself and don't use that as leverage to get back into your relationship. And I see now that you are apologizing, no justifications. That is good and respectable, and surprising uncommon. Yet still, it's another tactic to try and get back what you had.
The damage is done. There is nothing you can do to erase that or soften the blow. Words are great, but when you break somebody's trust, they are more or less meaningless. Actions dictate more than words do, and your actions right now are telling your story: you are trying too hard to prove something. The problem with that is that if you know you have something and are confident in what you have, you will not have or feel the need to prove it.
Why is NC so powerful, important, and necessary? Because it is confined to just you, it is your opportunity to make serious internal changes, and most importantly what you are doing is for you and once you achieve that, you will not need to demonstrate that or vocalize that to others. Your changes will be shown through your behavior and it will be noticeable to those that know you.
Most importantly, NC is not selfish. Your girlfriend dumped you for a reason and it wasn't on a whim. She's thought about it for a while and when they are ready to do that, there is nothing you can do to change her mind. By constantly bringing it up with her, pestering her with how you changed, it is just bringing back the hurt and pain caused by the relationship and will not allow her to heal. Even for your own sake, it is pushing her farther and farther away. That's not love. There needs to be space. Lots and lots and long periods of space. For both of you to heal and both of you to become better people from this tragedy.
There is nothing you can do or say to win her back. She will have to make the decision on her own. If she came back from your poking and prodding, like you hope, it would be for guilt or pity and I guarentee you will back here on this forum in the future.
Considering the length of your relationship, I would say your chances in the future are zero. That was one of my favorite pastimes during the initial break up was to try and calculate what my chances were and what I can do to increase it. The epitomy of selfishness.
Sorry if it was harsh or cruel. Expectations versus reality.
Waking up next to a beautiful girl,
Step outside and say hello to my beautiful world.