(((Amy)))

I'm so sorry to hear things are so hard right now.
Has your husband ever been open to seeing a couples therapist, even just a few times at least? Relationships can be SO difficult... I have found this to be so helpful, especially to be able to say things to my partner I couldn't say if we were on our own. It is a safe place to talk when you have a good moderator who understands...
From your post, it seems this other guy was putting a lot of pressure on you. IMO, better to try to work things out with your husband and let them evolve or resolve naturally first before tackling another relationship - which can lead to so much more stress and won't usually end well (again, this is just my opinion).

If he is not open to it, you might consider going to see a therapist on your own. (I actually see 2 right now, one with my partner and one by myself ). I think the internal aches in life will keep popping up if you don't address them, as they often come from way down deep or from a long time ago.
Sending many supportive thoughts your way.

Elana