I think there is no harm is ever saying "This has been a rough day", but that being said, that would be all that is said lol!! Myself? I would be absolutely livid if H was wonderful and happy after I said ILYBINILWY and I hadn't been happy. It would make me think that he didn't care at all.
Be happy and wonderful but offer support as well. Bring that coffee, if that is all. When she says something that could be misinterpreted say "What I hear you saying is..." And walk away when the spew starts if you have to
I know DB says-be the person you were, but you also have to take into account the person W has become. It may be "why didn't bring me coffee" today and "I don't want coffee" tomorrow...prepare thyself.
You are a really good person and you seem like an awesome father. You can only control what you do and what you say. I tell myself this a lot. It doesn't always work (as you can see), but it is working more often than not
I think one uses DB in a personalized manner...this is probably where a coach would come in handy