“It’s my ADHD” is an okay place to start, but it’s also his responsibility to manage his ADHD and get treatment in a way that will be effective for your family. If you’re starting to notice that these behaviors are impacting you or the family, it’s important to find ways to help him understand that.
“Lately I’ve noticed you’ve been doing _____. When that happens, I feel ____ or it impacts the rest of the family in this way ____.” Helping him get to a point of understanding where he remembers that it is his responsibility to manage his irritability, mood, and behaviors. If he doesn’t, it will only have negative consequences on the family and on his relationship with the kids. As well, as a parent, it’s important to model good help-seeking behavior so that gets passed on to the children as well.
There are a couple of books out there on loving someone with ADHD and they can offer other tips on how to address this further. Good luck!