a difficult role, being partner and supporting someone with diabetes. In my experience, the best way to help is to ask your partner what he is finding helpful or not, from his perspective.
On my wedding day, I put glucose tablets in my husband pockets, my dad's, my mother's handbag and my sister's. Then I stopped talking about sugar as this day was not about diabetes but i just needed to make sure that it was catered for.
Hypos are times when I do need someone calm and matter of fact with sugary snack available quickly. I don't need the orange box, but sugar and possibly some guidance about what will bring my blood sugar up quickly may help as I can get confused and stubborn. No one has ever been trained to use the glucagon kit, though I have vaguely explained to my husband what it was and how to use it.
Maybe, having some sugary snack (hypo cure) in your bag and/or car/and bedside cabinet is already a big help. And just being there to be aware of what is going on, but not actually doing anything unless there is an emergency, just listening when your partner wants someone to 'know about it all', not necessarily becoming an expert or a nurse.
I am grateful for my husband to be aware that there is a lot more about me than just diabetes. Diabetes is part of the picture but not all is related to it. It drives me insane when people link everthing that happens to me to diabetes, but on the other hand if they completely ignore that diabetes is part of the picture, this does not help either. Not an easy job, being type 3 (partner or relative of someone with diabetes), it sounds like you are doing a great job already.
I asked my husband how he adjusted to my diabetes after we met (I had had diabetes for 9 years before we met): he informed me that he bought a generic book about diabetes in a shop to find out about diabetes in general, then 'just listened to me'. He normally lets me get on with it, but does support me if I am in trouble/hypo and struggling, otherwise diabetes is not really part of our discussion.
My main advice is that if he cannot persuade me to drink/eat some sugar when hypo, then the ambulance or hospital is the next step if I am unconscious or not recovering, and we have never used this option so far, but I am lucky that I can function with very low and very high blood sugars without needing much help. He would probably know how to use glucagon if needed but my old kit ran out of date and I have not had it replaced yet, oops. Which reminds me that keeping enough stock and supply before it all runs out is another good idea, but that's up to me to make sure I keep enoug insulin and supplies, nothing to do with my husband, unless we are just about to fly on holiday : 'passport? insulin? meter? strip? baby snacks? travel insurance?'
It is a steep learning curve but it does get sort of routine after a while, with its ups and downs.
And yes, it does not follow the books so doing the right thing day and night does not guaranty perfect blood sugars as diabetes has not read the same books, unfortunately. A lot of factors influence our blood sugars, not just food, insulin and exercise. Once insulin therapy starts the pancreas can feel a bit less under stress and it is quite normal to get lower blood sugars. Quite a lot of people go into honeymoon and they require only a little insulin or even none for some time. This period is very variable.
I think that in early days it is important to keep in close contact with the diabetes team and /or GP as things can seem very strange and difficult to predict and doses may need to be adjusted quite often initially. With time it gets easier to make sense of it, most of the times, anyway.
Good luck, just fire questions away if it helps.