I don't post much anymore....and I am usually upbeat, but your story hit many cords with me. It definitely sounds like your husband has a sexual addiction problem to say the least. The key being is it is HIS problem.....not yours.
The question then really becomes what are you going to do about for YOURSELF? Can you live in this world where your husband has an issue. And this issue goes way beyond just a general affair....it is almost a sickness.
I see the similarities to the man my wife had her last affair with. The look for a specific personality type that is also looking for advice. Then the page gets pushed a little bit each time to see how far the seducer can go....a slow process and very thought out. This is often accompanied by statements about how bad the cheaters spouse is...How horrible they feel in their marriage, etc. Basically laying the blame for anything that happens on the unsuspecting spouse. Of course then their is the other half of the affair who has a whole world created in their mind that isn't the truth, but they will believe it.
What has happened with my wife's OM...He begged his wife to return home, played the reconcile game, and within three months was prowling for another woman. This continues to this day were he has even called my wife again....among others.
IT is a sickness by the sounds of things and in the end you need to protect YOURSELF.