Hi, BF.
You said, "I’m so fixated on impending D that I cannot pull myself back and think about what kind positive attitude I should be showing when I talk to him." I think what would help you most is to stop putting all your energy on what you don't want: a D. You're attracting more of that negative stuff into your life.
I know first hand how difficult this is, but try it. Try focusing on something else (something positive) every time the thought of D comes to you.
((((((((((()))))))))