Tweek_1984 said:One thing I do know, I'm not sure I'll ever be able to fully trust her again.
I think that you have answered your own question with that statement; without trust a long distance relationship is not going to work.
In my experience long distance relationships rarely survive, and the ones that do require a lot of work. I've been involved with people for a long period of time living in close proximity before those relationships, for various reasons, became long distance. In each instance, within a short time the situation became unworkable.
However, as others have pointed out previously, it would be much worse if she hadn't have told you, and her admission is surely an indication of the fact she still wants to make things work.
These are just my thoughts on the matter, I'm sorry if they’re not what you wanted to hear but I hope they aid you in your thought process. Just take some time to think things over, don't go making a snap decisions. Good luck.