bitter pill

(noun) a thing that is hard to accept

Example Sentences:

When Mike’s mother told him he could not use the car, it was a bitter pill, because he had a date that night.

A: Did you hear, the company is firing 20% of the staff?
B: What?! That’s a bitter pill.

From the Blogs:

Anti-Obesity drugs are a bitter pill to swallow

Media:

Similar idioms:

1. bitter pill to swallow
2. swallow one’s pride
3. hard to swallow