Free Doughnuts with your ADHD

So my wife and I are constantly fighting for numerous reasons. But we called a truce and started over last week. I've been taking meds again too  

Today she says "when you win a free doughnut you can't get a coffee. " (local coffee shop contest you can win a free doughnut)

I never go to this coffee shop so my question was: "that doesn't make sense, I don't get it. Are you saying you can't buy a coffee in conjunction with winning a doughnut? Or what? Explain. 


She responds "ya you can't get a coffee"

Me: "that makes no sense" you can't even buy a coffee?"


her: "don't be a fucking asshole, you didn't take your pill did you!!?"  You can't take a free coffee in lieu of the free doughnut!!


now granted I may have been having a blonde moment about the coffee  but I think the response was uncalled for. In frustration I walked away  

Thoughts anyone how I should have handled this??