Your heart already knows the answer to the question, your head knows too, tell the procrastination to take a hike! lol
If he can't be caring and understanding when you are obviously having problems then, IMNSHO, he won't be caring at other times either. Maybe it's time to cut loose, enjoy the time you have left with J before your trip and worry about the rest of it when you come back home?
There are as many ways to do polyamory as there are people practicing it!