E.D.
I have a GREAT idea (and I am serious). Why don't you schedule a family counseling session with a therapist while they are here to make some progress with your situation? Don't e-mail them to invite them or un-invite them. Schedule the session with you and your husband, and if your in-laws show up, include them; if not, go without them. Explain to your in-laws that you took their last comment to heart and are committed to doing something about it to improve the quality of your life and they need to be a part of it. If they refuse to go, go without them to let them know you are serious.