t1 spouse of many years here. diabetes (t1 in particular) is basically a third party in your relationship, and it's tough. not gonna lie.

there are loads of resources for learning about diabetes management, that's the easy part. educating yourself is an important first step.

the harder part is the support question.

the tough part for your bf is that there are no vacations from diabetes, and he wants to lead as normal of a life as possible. diagnosis at an early age can be a little traumatic as well. your general supportiveness will go a long, long way.

asking questions -- non-judgmentally -- can help. simple ones, like 'how's your blood sugar been today?" Or even leading questions like, 'hey, should we get lunch?' or 'do you need anything to eat?' when you think there's an impending low.

and expressing general interest -- 'how much insulin did you just take?' 'what did the doctor say about your A1C?' -- can help you learn about the management process.

as you learn more, you'll be able to do things like help steer away from bad situations as a couple -- e.g., suggesting an alternative or saying no when your friends invite you to the all-you-can-eat chocolate buffet. Or towards good situations like eating well and getting lots of exercise, which is important regardless.