Oh boy. I'm there, honey. I can relate. What has helped me is to realize that it's not about me, it's about him. It is his burden and until he "chooses" to overcome this, it will be the same. In the meantime, I go on with what makes me happy. And you're right, it is easier said than done, but you can't help him overcome this, the only thing that you can do is to be patient. In my sitch, my H of one year (2nd marriage for both and we are in the mid-life crises age), he had an A with someone 20 years younger than him. Do I think it was a mid-life crises, absolutely, and now he is a walking, talking depressed man. Some days he's okay, other days he sees all the damage. I've decided not to meddle but to be patient. If he wants to talk, I listen, if he wants quiet time, I give it to him. I let him set the tone because he has a heavy cross. I have put the A behind me (daily struggle, but I'm trying hard) and decided to make the marriage work. It may or may not work, but either way, I leave in great shape - nothing to be ashamed of. I don't know why you and your H were separated, but my H and I were too. I left and was gone for almost a year. I'm home now, things are going great, but there are very dark clouds at times. Good to hear that you both are in counseling. Can you go by yourself and express your concerns to the counselor and then when you and your H go together, the counselor could skilfully ease into a talk about depression, because that's what it sounds like - a good dose of depression. Getting older is no fun, especially when things got screwed up and everything that you've worked for, character, respect, honor and admiration are now all out the window because you screwed up, big time. It's hard to overcome, but it can be done. For your H's sake and your family, find some help for your H before he makes a decision that will affect so many lives.
Remember, you take care of yourself. You must be strong right now because you are going to have to carry the load for now.