Welcome to ThisIsMS, Gwynne.
Crohn's disease along with MS is in the "autoimmune" category, which has about 100 diseases/syndromes. And with your husband's diagnosis of MS, you are more than welcome here.
Concerning your husband, you have said, "I just don't know how to help." If you like to read, start your reading with two books:
Multiple Sclerosis: The History of a Disease by T. Jock Murray, OC, MD, and I think
The Multiple Sclerosis Diet Book by Roy Swank, MD, PhD and Barbara Dugan is a good second book to read or even have. I think even information on the Atkins diet might be helpful. You may be able to get these through your local library.
I believe insulin is a major player in MS; I encourage you, your husband, and your daughter to eat a healthy diet (a good idea whether or not one has MS) –I think the diet should not trigger insulin production. Many people find that diet can influence the symptoms of MS; there are several diets described in our Diet forum. In my opinion, this diet should be a very low-carb diet --remove ALL trans fats; remove all sugar (including beer, wine, etc. which have sugar), remove all artificial sweeteners, including sugar alcohols like sorbitol, xylitol, etc. (These promote insulin production, too.), and remove white flour, white bread, white potatoes, white rice (in fact, all carbs so far as possible).
My suspicion is that Fatty Liver Disease is also involved in MS (one can be "skinny fat" – slender with interior fat), since visceral fat (belly fat) secretes cytokines (like poison to the internal organs), which lead to increased insulin, which leads to inflammation which leads to more visceral fat… And the cycle goes round and round. Diet is important; in fact, you may find the account of Dr. Terry Wahls and her dramatic improvement in MS interesting (
http://www.TerryWahls.com). Maybe a careful diet, especially with added omega-3 fatty acids (found in fish or krill oil), would improve your husband's mood.
All the best to you.