a little hate goes a long way

As I mentioned in an earlier post, my girlfriend broke up with me recently and moved out. I was pretty sad, but I was ok. Then, a few days ago, I found out that she had slept with some guy back in April and hadn't told me about it, and, apparently, wasn't going to.
That added a nice big dose of hate to my emotional stew (as a consequence, I broke a bunch of her shit that she left at my apartment and made her get the rest out immediately). But, I also felt a lot worse. Without this revelation, I could have looked back on the relationship later in life with nostalgia, some sadness, but basically good feelings. Now, I fear that I'll look back on it solely with loathing, convinced that I wasted a very important part of my life on someone who really wasn't very cool.
On the other hand, maybe the hate will help me get over it faster. Knowing that the sight of her will make me nauseous might help me put to bed any lingering desires to get back together, and it will convince me that it really was her problem, not some defect in me, that pushed her away.
Happy to spill my beans of the carpet of the internet.