“Burn out”

“Like a fish out of water”

Uncomfortable in a new or unfamiliar situation.

“Better late than never”

Doing something late is better than not doing it at all.

“Shape up or ship out”

Improve your behavior or leave.

“Out of your depth”

In a situation that is too difficult for your knowledge or ability.

“Make a mountain out of a molehill”

To make a small problem seem much bigger than it is.

“Go out on a limb”

To take a risk by saying or doing something.

“Wrap one's head around something”

To understand something complicated.

“Burn the candle at both ends”

To work too hard and not rest enough.