From his perspective, you changed and are no longer as concerned with him. He might be fearful that you no longer care as much, or that you don't need him or like him as much as you used to. I wouldn't go so far as to say that he likes seeing you upset, just that he's gotten used to certain reactions, and now that he doesn't get those reactions, he's not sure what to deem as affection from you.
I know you already are doing this, but keep up communication. Keep him updated, repeat yourself if necessary. It might take him a little while, but just keep at it.