SADNESS
eat one's heart out
to be very sad (about someone or something).Bill spent a lot of time eating his heart out after his divorce.Sally ate her heart out when she had to sell her house.
in a bad mood
sad; depressed; grouchy; with low spirits.He's in a bad mood. He may yell at you.Please try to cheer me up. I'm in a bad mood.
in the doldrums
sluggish; inactive; in low spirits.He's usually in the doldrums in the winter.I had some bad news yesterday, which put me into the doldrums.
with a heavy heart
sadly.With a heavy heart, she said good-bye.We left school on the last day with a heavy heart.
Woe is me!
I am unfortunate.; I am unhappy. (Usually humorous.)Woe is me! I have to work when the rest of the office staff is off.Woe is me. I have the flu and my friends have gone to a party.
SADNESS - CAUSE
tear someone up
to cause someone much grief. (Slang.)The news of Tom's death really tore Bill up.Bad news tears up some people. Other people can take it calmly.