Going through the same thing after an 11-year relationship(she announced the divorce over the phone, then 2 weeks later was already sleeping with someone else…). It hurrrrts. Baaad. And she said what folks here are guessing, to me: that she had been thinking about it for awhile. Next question I had on my mind after that is: why couldn’t she have communicated better with me all along? The truth is I already know: she does have feelings, the problem lies in how she’s choosing to deal with them, and how different that is from how I choose to deal with my feelings(her way: closed-in-by-fear vs. my way: out-in-the-open-and-brave).
But eventually, it feels better just to work on restoring my faith in love by keeping whatever dignity I have and moving on in my own way. It can happen faster than you think, too. But never fast enough, hehe. Still, the best thing seems for me to keep moving. Such is life: change, and learning to deal with change.