Take it a step further, what would the result be if you contacted OW's H? Would he confront OW and beg her to leave your H alone and she magically would and your H would go back to his normal self? The likelihood of that is small. He has to be noticing the same things you and S are. The short term satisfaction would not be worth the anger you will unleash in H towards you. Is this fair, of course not, but you are doing what is good for your M, not theirs.
I agree IC would do H wonders, but until he sees that for himself, I don't know what good it would do. He has to realize it to some point if he is taking internet drugs for depression.
One of the DB things was setting goals. So, what are your goals? This small step sounds stupid, but if you stop before you act and ask yourself if your actions are leading you towards your goal or away, it can affect your actions. I remember Ellie used to keep index cards in her pocket with some DB principles and refer to them during the day.
And I love the cheeseless tunnel analogies. What you have done in the past hasn't always worked, change things around, try new things. But first, read the part on goals and set some! Put them in writing, this is a great place to keep track of what you are doing and have friends to keep you accountable.
