Is my marriage still doomed?

[AnotherStander]

Well my plan to refrain from sex was derailed rather quickly. One day of no pressure and I received two things. One was an email from my W, which said among other things that "she was a very very lucky woman to have a man who would stand by her through this," and then the following morning we had intercourse. All I did was put my arm around her and she wanted more.
Is this about control? ....But whatever, the point is that the attitude of backing off had an almost immediate effect. I will keep this position.

Wow, well it rarely works that fast but I wouldn't complain if I were you Hopefully you learned the lesson that loving detachment works, so keep it up!

It is the issue of intimacy and physical affection in general that seems to be a sore spot. She will be cold then suddenly hot and then back to cold again in this department.

This is pretty typical behavior actually. How are you responding to the hot/ cold cycles? Here is something brilliant Accuray posted on this, I liked it so much that I copied it to my DB forum notes for continued reference:

"Another thing to expect is that your wife will run "hot and cold" -- she'll be nice to you one minute and the next will shut down hard. This is extremely confusing. Here's what's going on -- your wife will "try on" being nice to you to see how it feels, or if she gets comfortable may slide back into a familiar partner role. At some point she'll catch herself, will worry that you'll get the impression that everything is now "okay" when for her it is not, and will then make sure to demonstrate to you that everything is NOT okay by shutting you out and pushing you away. That's all an inner dialog so to you it just looks completely confusing. If you expect it, you'll enjoy when she warms up and won't worry too much when she goes cold.

It's tempting to get into a mode of catastrophic thinking -- that each time your wife goes cold you worry it will stay like that forever, or "oh boy, this is it, she's gone!" That leads you to panic and overreact. This is a roller coaster, and there will be very dramatic highs and lows. The best thing you can do is try to stay near an emotional baseline. If the WAS bounces between 10 feet up and 10 feet down, the LBS tends to go 25 feet up and 25 feet down in response. Your goal is to go 5 feet up and 5 feet down instead. Take the long term view. Easy to say, hard to do, but if you know what to expect things get easier."