Thanks friends.
Actually, Jack asking aroung for Ennis's whereabouts must have bothered Ennis and contributed to his paranoia. Plus, I suspect that didn't really want to be seen with Jack -- consider that everytime they met after the reunion, they agreed to meet up in the mountains, and not in town or at Ennis's home.
And yes: I think that both fought their miseries alone rather than together. For Jack in this scene, he just didn't want Ennis to see him so vulnerable. Perhaps she should have allowed him to see just how vulnerable he was.