You are caught between a rock and a hard spot here because of your sons and having to communicate w/your h. Andrew's posting is something that you need to re-read and then think hard on what he's written. Sometimes, as humans, we look for that one special opening to start communicating w/them again. I did it too...so I do understand what Andrew is pointing out. If the contact is keeping you from detaching more, then you may want to consider only responding when it is necessary to do so.
Your sons are grown and whatever relationship they forge w/their father is one that the three of them will need to rebuild. Yes, it's okay to be a part of that...but be careful...if co-parenting in a "closer" environment is going to cause you stress and anxiety, then it might be time to let them figure things out. As for family events, such as weddings births, family emergencies, both you will be there front in center because you both are parents. Again, I do understand where you are coming from.
As for the job front, I'm so glad to read that your manager/supervisor is willing to work with you on your position at his/her company. That says a lot about how great you are as an employee and as a person.
Lou, take each day as it comes and don't look too far ahead. You know that people in crisis change on a dime and he may want a connection w/you at the moment and then disappear down the rabbit hole again for a while. Please sit quietly....the answers will come.
Please take care of yourself.
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.