I don't think he had any self consciosness about his face or his not contacting her at all.

I think he was deeply focused on his new serious role in the family business, taking care of his father, and didn't really want Kay back in his life yet. She would just be nuisance with the big job of moving out to Nevada. Of course, in the book, when Kay finally does meet Michael, he doesn't refuse to start seeing her again.

It's curious that it's actually Michael who seeks out Kay in the film.