“Anybody have suggestions as to how to handle Shabbos..”
I find that the shabbos table alone has a tremendous power to bring happiness to people, frum and not frum. Therefore, don’t under-estimate how effective the shabbos table can be in helping your child feel happy and loved.
Some possibilities to make the shabbos table more fulfilling could be as follows:
-allow your son (and other members of the family) to place a request for a certain types of food they like.
-possibly start each meal with an interesting story (jewish or not jewish), about a person was faced with hardship, and how they dealt with it. Then invite the family to provide their own opinion about the story or any other lesson they wish to add.
-also, singing is a powerful tool which brings happiness. Encourage your husband (and children who wish to sing) to do so. Though it should not be forced.
I hope that your son and all other children who are thirsting for the beauty of a jewish life find it soon.