Since I have a spouse with diagnosed ADHD who is constantly tardy, forgets things, forgets to tell us things, mislays items in the house then goes on a rampage to find them and blames us for moving them, and has done some pretty egregious missing of important deadlines (taxes, visas, work deadlines, missing airplanes, weddings, etc) because he refuses to medicate himself or build a routine and systems for himself...
... I both sympathize and ask: is it that bad that your every day life is impacted? Because if it is, then you've got a real problem. Your husband needs to be assessed by a psychiatrist and try meds for ADHD. If it's not that bad, then you'll have to talk him through trying to be more responsible. And maybe it won't work. And then you'll do more than your share, just so that things run smoothly, and you'll gradually be incredibly resentful. Sadly, I have no answers to that because I'm looking for solutions too.