New, dazed, depressed and confused...

[Ahoy]

Don't worry about endings right now, just take care of yourself and focus on yourself. Is he still living at home right now? Are you pursuing him, or are you giving him space? Are you going no contact?

Everything he is doing is very stereotypical of people in affairs. It has very little to do with you, so don't take it personally. That being said, now is also a good time for introspection to see if there are things you should work on for your own sake to make your next relationship (whether an entirely new one or a new one with your fiance) even better.