Managing multiple restrictions in diet: Cancer and colitis

I am desperate to help my husband find food he can eat and hopefully enjoy! 4 1/2 years ago he was diagnosed with melanoma and I read up on cancer preventing foods, trying to encourage him to eat things like whole grains and veggies. Over the past years he's found that he has autoimmune, genetic predisposition to other cancers (has had 6 surgeries to remove growths on skin and organs), and then a year ago found out he has severe colitis! We were corrected into only white bread, no veggies... a lot of what he was eating was now off the list of choices. So it's been challenging to find good & safe food. One of his few pleasures has been the fresh eggs my son's chickens lay. Now his GP is telling him his cholesterol is high and eggs are a bad idea. I want to support him and give him food he can enjoy but it is very challenging. Does anyone know where I can get some good dietary support for his needs?