Hi and thanks for writing back.
You know there really are no strategies to help him to communicate with you and sadly this will in the long run hurt him more than anyone. The sad thing about adults is that they get stuck in lifelong patterns of behavior and unless (most unfortunately) something very drastic changes, they do not change. I know how frustrating it is for you because it is so frustrating for me as a therapist.
You know when clients ask me this question I tell them to vary their approaches but even with varied approaches it almost never works. Your husband may behave as he does in part because as you said your mother in law is not a complex or sophisticated parent and so your husband deals with you in a rather primitive way. I do not know specifically how you undo that lifelong conditioning without talking or therapy but he is behaving poorly and most childishly and it really does not have to be this way.
When I first read your post it made me a little angry that you have to endure this nonsense and one of the first thoughts that came into my mind was quite passive aggressive (something that one of my clients did some years ago when she was in the same situation as you find yourself today...........I thought to myself that the next time your mother in law comes to town, you should greet her at the door with your husband and then whip your suitcase out of the hall closet and kiss them both goodbye and say......, Well I am off for the weekend, my girlfriends and I are having a girls weekend at Annies cabin in the mountains and so that will leave you too lots of time to spend with each other. Sorry there is no cell phone reception there so I wont be able to call you but have a lovely weekend!
I know you cannot do that, but I like the element of surprise and catching people off guard and I know when my client told me this story in a therapy session I did laugh (guilty as charged) but think about things that might shake up your situation and if you feel it will not cause more backlash to harm you by all means do it.
In the interim please spend more time taking care of you and doing things for yourself that you like and less time taking care of others. I do not think you are as appreciated as you surely deserve and if something gives you joy (painting or music or joining a book club or gardening whatever you like.....) please start spending more time doing it. I think you deserve the comfort and joy small pleasures often bring.
If things do not improve or worsen, please do not stay. I know how hard it is to even think about leaving but Major Depression is a very serious illness and you do not need to endure that level of pain again.
Be well and good luck to you.