Wiktionary
bummed out
(context slang English) depressed, disappointed, in a gloomy mood. v
(en-pastbum out)
Usage examples of "bummed out".
It was funny, but she didn't feel nearly as bummed out about it as she thought she would.
No matter how secure you are that you honest to God had not sent someone to a madhouse, theres always that little core of doubt, and saying what shed said just bummed out my head.
And at first I was bummed out, because all the ones I saw were racist.
He had a peculiar air about him: tense and bummed out both at once, a sort of dulled urgency.
My dad made it sound like you were really 'bummed out' for what reason I do not know since it seems to me that you did everything you could to make things turn out right.