He may not have a choice in working, especially if he informed the boss and the boss didn't change the schedule. As for the tickets, is there anyone else that can go w/you? You may be able to sell the ticket at the venue, but may have to take a loss.
I'm very sorry this happened.
Sit quietly, the answers will reveal themselves when you least expect them to. The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.
