Hope, we are in this together. Ok? I am worried you will feel like I am attacking or something. I am only trying to help any way I can.
Clarify? I will try, first the easy one. You have every right and should IMO try to enforce boundaries, schedules etc regarding your S. You were right to react to that and I am glad you can see how he takes things for granted (that you will be accommodating, you will agree, he has options depending on HIS schedule etc etc).
Then regarding the minibomb and rubbing OW in your face. If you go back and read what you posted, because that is all I have- you will see you felt hurt, disappointed and disrespected by ...what exactly? By his words he was in the city. That was all he said. And yes you may know that's not like him, but it's not the him you knew anyway. And I dont doubt you are right with your assumptions but what about the other days he is probably with her, the days he has no reason to contact you because of your S. You cant let the hurt go but dont let it affect your interactions with him. You have made it clear you dont want him sharing details, if he does, then respond.
I wouldnt even reply with what you quoted. Just plain "you are interupting my schedule, got to think of a solution" or "this is not what we agreed but let me see what we can do" and when he meets you to pick up your son, you make it clear that you will not accept change of plans without prior agreement. WHY would you tell your H your "mind is running to different directions"? Why?
Hope, this is essential and VERY important. DO NOT have any expectations from your H to understand, validate, help out at this phase. If he does, fine. If he fails to, fine. Try to keep your moods balanced, and yes, self soothing. You are in charge of taking care of you, no one else. Not eating sounds bad. How can you think straight when your body is starving? Please, you are a mom, you are responsible towards your S as well. That is much bigger than your H. Go eat a pizza!!! Hugs K
You should feel good about letting S go to his dad. It's wise and right. Do it with a smile (until the door closes)