I don't know if you have sent it yet or not, but I'm not sure about the letter you posted. While it does contain some good points that need to be discussed, it also has a tone of willingness to make this D quick and painless for him. He needs to know that you will not actively resist D, but you also will not help. He's probably not as eager to get this done as he's trying to make you believe he is....watch his actions, not his words. Related to this is unfriending him on FB. While it will help you preserve your sanity, he could see it as a step you took toward ending your relationship. You don't want him to see any of those.
The other thing, which you probably know is that your S4 is confused right now. If you can get your H to establish some sort of routine with him, it would help him a lot.
BITS M: 35 W: 35 T14, M11 D9, S6 ILYBINILY: June 09 Unofficially Separated (long distance): 1/2/11 W came home: 3/17/11 EE: July 2012 Dropped the rope: Oct 2012 Piecing: April 2013 Not piecing: April 2014 Stuck.