I'm no expert, but one thing I learned from my DB coach is that it is important to make sure that you don't minimize his down feelings in any way, otherwise they think you don't get them.
so don't in any way say that it isn't as bad as it seems, or point out why things are "really" good
validate his "bad" feelings, by maybe repeating them and telling him you can see how hard he is stuggling.
I think someone said it already, but don't offer him solutions.
If he feels like you get him and understand him, I think it would be less likely that he'll turn to the MOW again. At least that is the tie that binds my H and MOW - she understands him - and in hindsight (with Jody's help) I see that I was minimizing things he would open up and tell me about. I'm an optimist, so it is hard, but I am hopefully getting better at not minimizing.
One thing I think you also have going for you, is that your H can blame some of his bad feelings on his perceived failures with his work (I think I remember that being true for him?). That takes some of the heat off of you. In my case, my H has been doing fabulously with his career and always has, so it must be that he married the wrong person and that is why he was so unhappy.
stay strong BA!
Nature Girl M 40 H 40 M 15, T 19 D11 S9 bomb 3/07 (MOW)