You should have a little meeting with his mother, maybe the two of you go out shopping and/or meet for lunch and get to know one another better and see if you can't at least understand each other even if you don't become good friends. You can't really know what his mother thinks of you unless you talk to her; "vibes" or his side of what she thinks is not the same. When I get anxious about another person, I think of the TV show, "Dharma and Greg" and how they make it work.

Work on solving the problems/stresses instead of giving in to them. There's no way giving in to them can help. It's a bit like nightmares where you're being chased; you have to turn around and face the monsters before they'll go away.