Congratulations on your breakthrough -- it must feel wonderful. I would like to add to everyone else's words of caution, however, and encourage you take things SLOOOWLY, and to realize that it was very likely the OM dumping her that precipitated her change of heart.
Also, I would implore you to put a good strong transparency plan in place, as the recidivism rate on these things is very high. This does not have to be forever; just until you can begin feeling safe again in the marriage.
