If you are confronted with a problem, task, or difficulty, you have to deal with it. She was confronted with severe money problems. If you confront a difficult situation or issue, you accept the fact that it exists and try to deal with it.

Is it confronted with or confronted by?

The ngrams suggest that confronted with is more common than confronted by in both BE and AE. Certainly I wouldn't call either wrong.

What does it mean to be confronted by someone?

To confront someone is to meet with a person with whom you disagree or whom you will accuse of something: I had to confront him about the damage to the car.