If you are sad and can't be cheered up, you're disconsolate. Why were you disconsolate after scoring a touchdown? Oh...it was for the other team.
In addition to meaning "inconsolable," the adjective disconsolate can also mean "dejected." Most people would be disconsolate after being laid off from a job, losing a beloved pet, or missing out on tickets to see a favorite band play live. This word ultimately derives from the Latin verb consolari, meaning "to cheer (someone) up or offer comfort to."