MOST IMPORTANT (So I will repeat): Whatever you do have zero expectations for what your spouse may or may not do.
FYI: My W dropped the bomb on me just a couple of weeks before our 16th anniversary. I got her a card that said what I wanted it to without saying too much (that is now the hardest thing to find when it comes to greeting cards for the WAS.) I then added a few poignant sentiments to make it more personal. And I gave it to her realizing that she was not likely to reciprocate. It still hurt when that turned out to be the case (all she could say to me was, "Why now? It's too late!"), but because I was already mentally prepared for that, I outwardly took it in stride.