As many people have said, be happy that it happened when it did, before kids/mortgage together and all kinds of enmeshment.

I think you need therapy for yourself. The meditation class you have been going to is not helping you. I cannot do meditation, unfortunately, because I get bored, but I have gone to meditation classes and have read about meditation. So my understanding is that the meditation is supposed to help you be in the moment and accept your present reality "as is", more or less, and you are, instead, desirous of changing the reality in very drastic ways. Given what the guy did, there is clearly no point in moving forward with him into the next stages of your life. It would take a miracle to change the guy. So in addition to seconding Bonnie's suggestion to avoid the meditation class for awhile in order to avoid seeing the guy, I suggest that you reconsider going to the meditation class altogether because it has not been shown to be effective, in your case.

Since you write about career success, it also seems to me that you might be a high achiever driven to want to face extreme challenges. Yes?

To work it through with him would be an extreme challenge. It is much easier to find another man. If you have the drive to overcome extreme challenges, you probably need therapy to help you refocus the drive on something less personal - say, on choosing the most difficult projects at work. At work, your choosing and then successfully dealing with the most important project may lead to something positive - the respect of your colleagues and managers, promotions etc. In your personal life, even if, with the help of a miracle, you could go to the next stages of your life with this guy, I doubt that you will get any gratification from it.

Again, to second H3rmit, please be grateful that you do not have children with him!