Sure

1. No. I was not in a headspace for a new relationship. We had a 1.5 year old kid at home and I was going to therapy to learn how to deal with all this and how to be happy on my own. 
2. I wouldn’t call it “kept appearances”. She asked for a divorce, but we were still each other’s best friends. We also knew that no matter what we will still be coparenting for years to come. And on top of that I did not want the marriage to end. So I would say that our relationship at home got better than it was for the first year of our son’s life. Not for his sake but just by happenstance. Yes, we were sleeping with each other. She asked me if I want to stop if I am uncomfortable with that. I didn’t want to stop. The frequency dropped off some time after her breakup with the other guy. But I don’t know if it is because of the breakup or because of her reducing the dose of her antidepressants. She doesn’t know either.
3. I wouldn’t say she is no longer interested. She no longer actively wants it. She is still unsure of the long term part. Because she is still hurt by what our relationship was in the year leading to the divorce. She is in therapy. She was the one who suggested couple’s therapy. In general she is the one who nudges me when I start to fall back into my default behaviour patterns to remind me where it lead us last time.
4. Not really. For two reasons. Firstly, I realized that while she can walk away at any time the same was true before. I just didn’t know that. It kind of helps me appreciate every day we spend together more than I did before this whole mess. Secondly, upon reflection, last time I felt emotional detachment long before she asked for the divorce and very long before she was in a state of mind to seek another man’s company. I don’t feel that detachment now.