Firstly, welcome to the forums. Secondly, I'm sorry you felt used by that experience. That is certainly an understandable reaction.
I want you to consider for a moment that perhaps he didn't do it maliciously. Perhaps he became uneasy about the idea of entering a poly relationship dynamic, and just didn't have the courage to talk to you about that. Or perhaps he had an SO on the side who discovered him cheating and put the kibosh on it. Or maybe he discovered you just weren't his cup of tea, and, not liking confrontation, decided to end it by ignoring you. Or maybe he's in a sensitive job and started worrying this kind of lifestyle would "out" him.
The point is, you don't really know why he became incommunicado. Try not to assume the worst in the men out there. Maybe get back out there, meet some guys, have some fun without putting the pressure on yourself to meet your perfect poly-guy. Be upfront, honest, have fun, and don't make this a race, or feel you need to keep up with your husband. Make sure he's paying a proper amount of attention to you, let your feelings be known, and keep posting here to let us know how you are doing.