A vet will need to chime in, but limiting contact is a last resort technique.

In general, if you're not at the last resort, they say that remaining in the same house and in contact is best, so that your 180s and positive interactions have an affect.

Can you give a short run down of the situation again, so the vets can advise better?

ME: 38
BF: 40
T: 10y, no kids, no M (by choice)
BD: 7/14/14, BF admits to PA, wants out, lies about new R.
10/1/14: I move out, BF lies about move in with OW
12/4/14: OW confronted, reveals all the lies