Comedown suggests a troubling event with a negative emotional effect on someone. He viewed the demotion to a clerical role as a comedown.
Pro Tip 2/3
Previous Success
Used when comparing someone's current situation to a more successful, happier past. Moving back with his parents felt like a comedown after years of independence.
Pro Tip 3/3
Relative Status
Comedown implies a drop from a relatively high status or position. Her assignment to the minor league was a comedown from last year's spotlight.