rob, Sorry to hear about this problem, but this is the reason divorce in our country is so high (I think I heard over 50%). People have forgotten what "commitment" is all about. Your wife may think that her "new life" will be better, but she's going to have other problems not evident now.
You have no choice in the matter; she's already done that for you. Try to not linger and create a new life for yourself rather than stewing over the past.
There is one lesson here for you; think about any future relationships about "irritable, sharp tongued, and not happy with the relationship." We all make mistakes, but you now have a chance to improve on them. Give it a shot, and good luck.