I've offended my in-laws

Stealth sounds like a very good idea. Many intelligent and lovely men (my partner for one!) have quite limited means of letting off steam or sharing their fears, about a lot of things. I have to confess that a support group wasn't entirely appealing to me but individual counselling was really useful to me for a relatively short difficult period during treatment and my partner did give it some house room when he required treatment after surgery a few years later. But letting a few mates know that keeping him to a night out occasionally or something similar, may work well.