I'm happily married, but man what I wouldn't give for my wife to do that.
Seriously, I'm going home tonight and tell my wife I'd like her to whisper those sorts of things in my ear.
I've never really read much on men's libido issues, because I've always had the opposite problem, but I have caught little bits here and there through things I've read. For men, having a low sex drive is a HUGE issue. So much of the foundation of who a man is supposed to be is based on sexual prowess, and all men know it. It's stupid and archaic, but that doesn't mean it isn't true. It's very hard for men to deal with sex problems, and often men deny it as a real issue and instead of trying to resolve it, just get angry whenever the subject comes up. From what I've read, getting a man with a low sex drive or performance issues to be open about it and work on it is VERY difficult.
That all aside, this is one case where sex really isn't the issue. I've read through your previous post and everything runs so much deeper and farther than that. Even if you resolved the sex issue, I don't think that would affect any change him in regards to how removed he is from your needs and the marriage. It sounds like you are so incredibly unhappy and getting no where no matter what you do. It also sounds like your biggest worry is your daughter. So many people make the decision to stay together for the kid(s), forgetting that children often feed off of the emotional stability of their parents. If you're constantly unhappy, depressed, and going through wild mood swings with your husband, is that really better for your daughter than sitting her down and telling her what is going on and letting her know you think it might be time to try a separation? She's old enough to handle it, probably better than you think.
In no way do I condone the idea of an affair though. It never resolves anything. Will it shock him? Like you wouldn't believe. But the odds of it being a shock your already fragile marriage will survive is pretty low. Don't for one second think he wouldn't care. Men are incredibly jealous and territorial about their spouse. Your husbands response was straight from anger, possibly directly related to his performance anxiety. I can practically guarantee you he'd be emotionally destroyed if you actually slept with someone else. Not a great way to try and repair a marriage.
You really need an honest conversation with him where you set (i.e. write down in complete detail) goals for each others needs, short and long term, and then come up with explicit steps you need to make to reach those goals. And he needs to know that those are your minimum requirements to be happy in the marriage. Make sure you let him know from the beginning there are lots of things you plan to work on as well, it will keep him as open as possible to what you need. Write it out like a contract that you sign and agree to with the knowledge that it is a marital contract. Fall short or backslide too much and there are repercussions. Plan on revisiting your contract a couple times a year (or more often in the beginning) to go over your progress. If he is unwilling to meet them or compromise enough, then let him know you have to do what is necessary to ensure your happiness because you can't live any more as you are.