I had hypoglycaemia for years but, not the gastro.
While a BGL of 3.8 can make you feel awful, especially if sugars tend to run high a lot, it's not too low (hypoglycaemic episodes or "hypos" are 2.8 and under). I used to find that it was the sudden drop that would do me in rather than the level I actually sank to. With this condition the recommended route to follow tends to be multiple small meals/snacks throughout the day; keeping them balanced in protein, fat and carbs. This is the best way to keep sugars level.
Another common practice when you see an Endo, is to be referred to a dietician or nutritionist. They will help you build a lifestyle plan (diet, exercise, meds), tailored to your specific condition. It's a team environment, with everyone (including you) working together.
Try to relax a bit with the knowledge that you'll soon be having the right specialist addressing your concerns
Good luck and let us know how the appointment goes.
Kris