You don't have to agree to every nut-brain scheme your ex comes up with. Sharing custody of the dog???? Come on .....
The dog lives with you, he's company for you, you agreed he could have a sleep over with D14, he had it ... it often seems to me like you give an inch and she takes a mile.
Enough.
You shouldn't have to see your wife in the mornings during the week - not until you are way more detached from her.
Say NO. Make a boundary that puts your needs and healing first. It doesn't make you a bad man - it makes you a man who is taking care of himself.
Chin up. v
V
Never make someone a priority, who makes you an option.