Your game plan is to re-attract H you. Dress up a bit more flirty-ish and really make H think about you. Keep those interactions short such as 1 hour lunch then you two go back to your respective places.
Listen to H like a lover...validate, full-on eye contact, and be supportive. Zip it about your gazillion problems at the home with kiddie snot etc.
There will be fits and starts on the XOW front as there will be times when she'll try to suck H back into the affair. If not, then H will most probably be experiencing OW-withdrawal pangs. Like a drug addict trying to quit heroin.
Patience will be on your side and use it wisely.
You've got this!!
BTW...have you read any of Train's recent threads?