I don't understand why your doctors don't read the NICE guidelines for treating diabetes associated with pancreatitis. They state that Insulin is the treatment of choice. Adding in medication is flogging a dead horse. Tablets only work when there are sufficient cells to produce insulin, but in an inflamed pancreas, there just aren't enough, if any at all.
Sarah, I would suggest when you are seen at the next clinic, that you refer to the NICE guidelines, which as i have explained are screamingly obvious that Insulin must be used. It would transform the way you feel, it will be like a light turning on in a dark room. You don't need any blood tests for that to happen.
Incidentally, constipation with Creon is a sign that the dose is too high. The correct dose is that which gives you regular comfortable bowel motions. too little, you get loose motions, too high a dose bungs you up, or you get the same sensation that a chilli laden meal can, commonly called the "hot ring" syndrome.
You are quite right to say that constipation can cause diverticulitis to flare up. I can't tolerate a high fibre diet, because the roughage can slightly damage the lining of the colon, and that can trigger a flare up of the Ulcerative Colitis.