A mixed day with thoughts about kids health

Well, I didn’t seem to have the greatest day today as I was rushed from morning to evening. I have the feeling I haven’t achieved anything and still couldn’t decide what is the best path to adopt for my oldest son Ulcerative Colitis (one of the IBD conditions) and my youngest one sensitivities.
My current approach of gluten free, milk free (I give him homemade yogurt and some cheeses), additives free, colorant free and preservatives free … does seem to work but has limited success. I feel I’m at the end of my nerves going on this path tryiong to buy at least half Organic and avoiding the junk food and sweets.
The most difficult to avoid is sugar which is found in almost everything you can buy from the shops.
I guess I have the full night to figure it out.