Bite the bullet
To face a difficult situation with courage.

Burning the midnight oil
To work late into the night.

Between a rock and a hard place
Facing two difficult choices.

Throw in the towel
To give up or admit defeat.

Cry over spilled milk
To waste time worrying about something that cannot be changed.

In hot water
In trouble or difficulty.

Jumping from the frying pan into the fire
Going from a bad situation to a worse one.

A blessing in disguise
Something that seems bad at first but turns out to be good.

Elephant in the room
An obvious problem that is being ignored.

The last straw
The final problem that causes one to lose patience.

No pain, no gain
You have to work hard to achieve something.

A double-edged sword
Something that has both positive and negative consequences.

Kicking the can down the road
To delay dealing with a problem.

The tip of the iceberg
A small part of a much larger problem.

Make a mountain out of a molehill
To exaggerate a small problem.

Caught between the devil and the deep blue sea
In a dilemma with no easy solution.

A tough nut to crack
A difficult problem to solve.

Barking up the wrong tree
Pursuing a mistaken or misguided course of action.

Face the music
To confront the consequences of one's actions.

Put all your eggs in one basket
To risk everything on a single venture.