If you have diabetes because chronic pancreatitis means 90% of your pancreas is dead that would be type 3c diabetes. Usually if pancreatic function is as limited as you mention (I've only got 10% of it working as the rest of it is dead) you have to take creon and be careful about fat intake. As well as having no beta cell function (making insulin) you have no alpha cell function (making glucagon in response to a hypo) so you are likely to be a little more brittle, and have to be more careful of avoiding hypos.
Having type 3c doesn't mean you don't have to watch what you eat. If the nurse had assumed you were type 2 and diet was the cause that suggests you have weight to loose and it would be important for any diabetic to aim to be a healthy weight, as this will assist with insulin resistance. It's also important for any diabetic to be eating a healthy balanced diet. A type 3c is usually on a basal bolus regime with carb counting.