Hello and welcome to the forum. Your husband is very fortunate to have a wife like you
I agree with a lot of previous posters. Before I was diagnosed I was well overweight and the response of the doctor was quite often defaulting to 'it's because you are overweight'. It wasn't always (or even often) due to my weight.
So yes it can be easy for any medical profession to look at the diagnosis and blame everything on being a diabetic.
So before you see the endocrinologist on the 23rd my suggestion would be to do very regular testing of his blood glucose levels. Give him more information to consider. If the tests show that his levels are okay then that's something the dr can rule out. If they are high that's something she/he should know to consider in the overall picture. I would also suggest keeping a food and sleep and symptoms diary. It feels like a lot when you do this but giving the dr. more information can only help.
Good luck- I hope you get some answers!