Don't bite off more than you can chew!
Don't take on more than you can handle
You are barking up the wrong tree!
Taking the wrong course of action / to have the wrong idea / to ask the wrong person
His life is falling to pieces.
Fall apart / breakdown / become ruined
Save it for a rainy day.
Save money for a day where you will really need it
You are driving me nuts!
Making someone crazy
He turned over a new leaf.
To start over with a different perspective
The apple never falls far from the tree.
When someone looks or behaves just like their parents or relatives
I am under the weather today.
To not feel good
He squirreled away some cash under his mattress.
To save / hide
I am nuts about you!
I really like you
He is a bad apple.
One bad person in a group of good people
Fall into place.
To fit together or become organized
Fall head over heels.
To fall in love with someone
Don't fall behind.
To fail to keep up with the rest
I gave up soda cold turkey.
To stop doing something altogether or all at once
I gobbled up my dinner.
To eat quickly
