Idiom: Suck it up
Meaning: Stop complaining.
Example: Abby is talking to her teacher Mr. N, as he assigns the class some homework.
Abby: But Mr. N, we've already been assigned a lot of homework for tomorrow in the other classes!!
Mr. N: Well, now you have some homework for my class too!
Abby: But, tomorrow is Friday and we have to study for tests.
Mr. N: Abby, suck it up!