If you are doing all this in the hopes of getting sex, you are setting yourself up.
If you are doing all this because it makes you feel good and you could care less if sex was the outcome, you will be unaffected by her response either way.
I think you'd make a much louder statement if you did stuff for your kids... and just got her a card and a hershey kiss. Recognize her as your wife, but leave all the over the top stuff FOR HER out of it.
I think you need to drastically change tactics... get yourself through V-day as best you can. Then maybe we can discuss alterations in tactics.
Corri
P.S. I personally think your creativity is a wonderful thing, and I am so sorry your W can't/won't enjoy it with you. But... please, please, please don't make the mistake of taking her reactions as some sort of poor reflection of you. It is the very worst thing you could do to yourself.