Unless you have just acquired a respiratory infection, it is highly likely that your cough is an allergic or irritant cough. One possibility is that your cough is caused by one of a number of personal items your wife might use, such as perfumes, soaps, make-up and skin creams etc, or that your cough is caused by non-personal things such as kitchen or laundry detergent. There may also be some new exposure in your current home environment that you are allergic to, such as animal dander, which might be present even after the animal is long gone.
We recommend that you and your wife carefully consider each and every allergen/irritant that you have just become exposed to or just become exposed to in higher concentrations than in the past.
I think you have axiety related to being married. Relax & take a deep breath.