Mopsey, Set some boundaries! You need your rest and if that boy can't sleep, he needs to be speaking to his therapist about it. He needs to understand that you can't operate on just a couple of hours sleep, work a job, run a household and ferry your children around to their various activities. When he calls and you are asleep or he wakes you up, be courteous but cut the conversation short by telling him that you are going to bed. End of discussion.
I think you are going to need to be a bit firmer on those boundaries. This guy is trying everything to make you feel bad about the decisions he has made. Don't go there and it's time he stopped feeling sorry for himself and look in the mirror at what he's done to you and your family. He's drowning in self pity and he should be discussing this w/his therapist instead of trying to make you feel bad. I'm glad you told him how you felt, but you do not need to defend your position all of the time w/him. He knows how you feel. Again, set your boundaries.
I do hope that things improve for you over the weekend. The weekend will fly before you know it.
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.