Deb, My dear, there is only one thing you can do. Send him to her and start moving forward with your life. Your H chooses his own path. You choose yours.
He may change his mind after he is gone. There is no way you can hold him back. He will resent any attempts.
Try to maintain composure when you send him on his way. Let him know that it is not what you want but you accept the fact that he gets to choose. Let him see that you will not lose your grip. If anything, he will wonder if he is letting a good thing go.