NTE, you're breaking my heart, man. I don't know what I'm complaining about over in my whiny-ass threads. I'd like to know how your vacation went, too.
If you're determined to do your sex strike, and she's actually asking for sex (but the sex you described) I agree with the others for what it's worth. I would only add that you should be clear about your "headache." Don't make an excuse (like "I've got a headache.") Just politely say "I've decided not to have sex for awhile. Sorry." Your purpose is to shake her up and make her see that you won't fake it anymore, right? No sense in playing a guessing game, then.