leem - you are not alone in your feelings. I'm there with you. It's kind of like the chicken and the egg which comes first. The drinking because of the depression or the depression because of the drinking. I myself think that the drinking in a self medication for the depression. Unfortunatley alcohol is a depressent which makes the problem worse. But you can't treat the depression while he still uses alcohol. Now that the alcohol isn't working he's moved on to escaping with the OW. Now that isn't keeping the depression at bay. You have done everything you can. Eventually, hopefully he will run out of temporary fixes and will be forced to face the real problems that took him down that road.
But you and I both still love our A's and it hurts so much to watch this unfold. I think sometimes that we ouselves want to fix this for them, not as much from being a codie, but so that we ourselves can stop hurting. We struggle daily with the fact that we can't fix it. Comming to terms with that leaves us so sad that we start spiralling down the depression road ourselves. That's why we have to save ourselves. Even if it means loosing something we love dearly, we have to do it for our own sanity.
You are doing great, and I know it is just so hard to keep doing it, but you can.
B