I understand what you're saying although I do not have some of the health problems you are having. Blood sugar responds immediately to what you eat and drink. Putting it simply, carbs raise blood sugar and keep it high. Some kind of prolonged exercise like walking, swimming, running and biking help control blood sugar as long as you continue doing the exercise on a regular basis. I'm not talking about
marathon running, but even walking outside everyday for 15 minutes helps. This kind of exercise also helps bring blood pressure to more normal levels and helps you lose weight if you need to.
If you have Crohn's, I don't know how you have to balance that disease with diabetes, so other members with that need to advise you. Steroids (oral medication and shots) raise blood sugar and doctors understand this and advise patients to adjust diabetes medications for that.
It's rotten having to deal with all this but take one step at a time. Taking your blood sugar readings after you eat helps you understand how you're reacting to the food, so you need to do some experimenting. Maybe taking smaller but more frequent meals (mini-meals) can help. Sometimes, I eat salad or leftover dinner for breakfast, or eggs. I can't eat cereal because I spike terribly.
Good luck with figuring out your food.