If you value your marriage, maybe put things on hold with people outside of your primary relationship until you get that boat back on smooth water. Once the comfort level is there again, then resume activities slowly.
I'm no expert, I'm only in a triad, so any dynamic past that, I don't have much of a clue.
best wishes to the both of you.
37, M, married, 15 years, in a happy triad for the same amount of time. It's not always easy, but it sure is fun.