听到这我很难过。

I'm very sorry to hear that.

他感到很忧郁。

He feels blue.

我对你的不幸感到十分伤心。

I'm feeling very sad about your misfortune.

他情绪低落。

He's down in the dumps.

他意志消沉。

He's downhearted.

我由于失败而感到很沮丧。

I'm very depressed about my failure.

他显得很消沉。

He looks glum.

我很孤独。

I feel lonely.