Your H calls frantically over and over again to make arrangements for when he will see his son.. and then after you mention that Wednesday would work best for you and to forgo his initial request of Tuesday and Wednesday he drops all contact.
What does that tell me (someone with no psychological training)?
Priorities. Your H's priority at this point is definitely not your son. Seems it is his priority to put you back in the cozy spot under his thumb! I'd bet he's regrouping.. wonder what arsenal he's going to show up with next?
Changing the dynamic of this relationship has got to be better than maintaining the status quo.
