Feeling under the weather
Not feeling well, feeling sick or not yourself
Every cloud has a silver lining
Something good will come out a bad situation
Once in a blue moon
Something that rarely happens or doesn't happen often
"To be a piece of cake" means:
to be very delicious
to be very difficult
to be very easy
The ball is in your court
The decision or choice is yours
"To break a leg" means:
to have a serious injury
to wish someone good luck before a performance
to fall down and hurt oneself
That costs an arm and a leg
It's very expensive, costs a lot of money
"To break the ice" means:
to be cold-hearted
to fall through thin ice
to start a conversation in a formal setting
Let's break the ice
Start a conversation or say something in a social setting
They got cold feet
They are feeling nervous
I am all ears
You have their attention, they are listening to you