You have a reason to be angry, but you seem like you're feeling a little paranoid. It sounds like you want assurance that thing'll be okay, but such a thing doesn't exist. Things are never "Okay".
Think about this; you're lucky. You're lucky she even has the courtesy to tell you what happened, you're lucky she seems to care enough about your relationship to cut ties, you're lucky you even have someone that's capable of hurting you.
Pain is as essential to life as breathing, it's something that we all have to face, and it's a part of who we are. I won't tell you that your relationship will end happily, I won't tell you to stay together because it's healthy, I'm telling you not to give up because if you do, you'll regret it. You'll spend a good long time wondering and wishing about what could have been, maybe not forever, but for a long time.
Maybe things will go to hell, maybe you'll get bored, but I know you'll be hurt, no matter what you do, but you can't let the fear of pain stop you from being happy.
All things are fleeting, so instead of trying to hold on to them forever, cherish every moment you have with them. Live in the knowledge that they are temporary, and use it to keep them in perspective. Don't expect things to be ideal or eternal, just be happy that they're there.
Sit her down have a long talk, vent what you need to, get as many sincere apologies as you need, try patch things up and see where it goes. Sounds like you've got some real passion here, don't waste it.
Just because it hurts doesn't mean it's not worth going through. At the end of it all, you might at least be able to remember that, for better or for ill, you took things as far as they could go, that you had something special, that you were truly happy, if only for a moment.
