Mel -The journey is long and not easy, no matter the direction. You've been there and can see that. Admist your concern and care for your wife, the focus should be on you and your son. You can offer her lots of "outs and help" but that isn't going to make her internally want anything different. All the research in the world and all the groundwork you can do is a crutch for her to lean on with a possible promise. She has to desire the new life and no matter how much love we have for the A in our life, that's one thing over which we have no control - and it hurts.
It was hard to accept the advise I was given but each day I'm finding that it is bringing me a bit more peace when dealing with the A in my life. The focus is "What are YOU doing to make sure that YOU are healthy?" I applaud the fact that you're looking at a father-son weekend. What about Mel time? Working out (the Y has great programs for kids that could be at the same time)...dinner with friends...a walk after your son goes to bed...or other ideas that YOU enjoy. In that, you'll be able to deal with the things put before you in a much better manner. I doubted but have found that leaving/time away from the A doesn't mean you care or love them less, it's giving yourself permission to love yourself more and be healthy. What a great gift to offer your son. He'll see his dad a little less stressed (even if it's only outwardly) and he'll admire that.
Keep talking and keep seeking. You're heart is in the right place...