I know this $ucks. You are the very best at this, you know... and your H still somehow finds the one tiny way to get you, usually by leaning in more than you expected. (And in thinking about this-- were you expecting him not to acknowledge it at all and you could both just pretend it wasn't today? So by saying something he knocked you off kilter?)
Not to mindread, but I would bet that for your H this anniversary carries some of the same feelings as moving back into the MBR. He's probably just as discombobulated as you are about it. And it isn't a bad thing in my mind that he acknowledged that to you.
Anyway, I hope you were able to let those emotions flow through you. Like Cardinal and Sage are saying, you totally deserve to have these feelings. It is OK. And, you are really good at listening to yourself and knowing what you need-- I'd spend some time doing that today, and then do it, whatever that might be. Dinner, whiskey, dessert, whatever.
Is your D ok? I'm assuming she might also remember it is your anniversary today... what if the two of you watched a girly movie and hung out?
You're incredibly strong. You absolutely have this. Know we are all here for you if you need.
Me (46) H (42) M:14 T:18, D9 & D11 4/19 - 12/19: series of escalating BDs 9/20 - present: R and piecing