Yvonne,

I did not see what was the reason your wife said that was the reason for the affair.  What is the reason she gave?  Are you two addressing that?

You wrote: my wife will not fully commit to working on our marriage

I think your marriage therapist is bogus for having you two go on a trip together as a fix.  This does not address the underlying issues in my opinion.

For me that is the reason why you alone cannot save your marriage.  I believe you need both parties willing to work on it and re-commit to the marriage.

Mark