I was diagnosed in the 90s. I’ve taken medication on and off ever since, with the vast majority of the time being off. On the surface I’m very successful, probably the same as you, but struggle inside just completing daily tasks.

I suppose you’re struggling with something which is why you got a diagnosis. So try the medications if you want, start low dose and only increase if necessary. If coffee really helps, then a stimulant is probably a good starting point. You may find some doctors who are really hesitant to prescribe them. If that’s the case, find a new one who is willing to help without making you do a little dance for them. I’ve heard horror stories like requiring the patient to submit to drug tests, in person visit to get a refill, unwilling to prescribe more then 30 days at a time, etc. There’s no legal requirement for this in my state and probably none in yours.

Being diagnosed just means you have a more informed world view of who you are and things to watch out for. Have fun and stay weird!