Hope, I'm glad you came back to update us on what's been going on. The conversation you had w/your h is very enlightening. He's starting to look within and it's going to take him a while to find the answers. He still can't tell you exactly what happened to him and why. But, you can take this to the bank, he was being extremely honest w/you in this conversation. Take yourself out of the scenario for you are not at fault. He realizes that now.
Continue being a friend, but give him plenty of space. He now needs time to think and focus on his issues and how he's gotten to where he is today. I'm very sorry that your home has been sold. You both loved the place and I had hoped he would find a way to keep it. As for puppy, I'm sure you are enjoying him being w/you. Yes, your h is truly alone now, but that's really what he needs.
Hope, some day, he will return and will want to talk at length w/you. Listen to what he has to say, but don't ask a lot of questions for he can't answer them. He can only tell you what is in his heart at this very moment.
You did an excellent job w/his visit and conversation. You are healing and finding yourself in all of this mess. Continue moving forward.
Sit quietly, the answers will reveal themselves when you least expect them to. The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.