My advice would be to find out from your husband more about what kind of support he needs / wants.
What men see as support we women probably wouldnt.
I will start by saying the above is very true. As a man, I know a little about this. My first suggestion would be to be careful. Don't let him get into denial. If you know little about depression and diabetes burnout, please ask because this can be important and there are books available that can really help.
Next, you cannot manage his diabetes. You can offer help and need knowledge about about hypoglycemia and whether he is aware when this happens. You will need to know which foods, drinks, or glucose tablets (he wants) and the amount will bring him back above 70 mg/dl (milligrams per deciliter). You do not want to have him eat or drink too much and drive his blood glucose into hypoglycemia.
He should teach you how to use his blood glucose meter and record the time and readings if he should be unable. You should know that if he is unable to talk - do not inject insulin, but test and find out what his blood glucose meter reading is and whether to call 911, if necessary.
Learn how to count carbohydrates. If you are the only cook in the family, you need to know this. I had to learn for myself because I was a widower at the time of my type 2 diagnosis.
Ask questions on the forum for additional information. Hopefully, now that he is starting to open up, he will answer your questions.