chin up

(idiom) remain cheerful during a difficult period, don’t give up

A: Medical school is so difficult. I think I’m going to quit.
B: Don’t quit, my friend. Chin up! You will be sorry if you quit.

Chin up! Things will get better soon!

From the Blogs:

Keep your chin up Andy

Media:

Similar idioms:

1. keep one’s chin up
2. hang in there
3. throw in the towel
4. work up to