Probably a variation of the expression "suck up your chest," meaning roughly "compose yourself, bear your troubles, stand tall, and proceed."
suck it up (third-person singular simple present sucks it up, present participle sucking it up, simple past and past participle sucked it up)
- (idiomatic) To put up with something; to deal with something, such as pain or misfortune, without complaining.
- 2001, Ben Marcus, "Graded By My Students," Time, 8 Jan.:
- Some students suck it up and meet the challenge. Others look around wildly for someone to blame.