I'm on cloud 9.
I am very happy.
My lips are sealed.
I won't tell.
Blind as a bat
can't see very well
spill the beans
tell the secret
When pigs fly
not likely to happen
I lost my head.
I got angry or upset.
a coach potato
a lazy person
in the dumps
depressed or sad
let the cat out of the bag
told the secret
killing two birds with one stone
getting two things done with one action
My car is a lemon.
The car is no good.
Break a leg
good luck, hope they perform well
has a heart of gold
is very kind
under the weather
not feeling well
It's a piece of cake.
It's very easy.
walking on eggshells
trying really hard not to upset someone
like a fish out of water
very uncomfortable
Beating about the bush
not getting to the point
time flies
time goes by quickly
It's raining cats and dogs.
It is raining a great deal.