Freaked out. Stressed. Going a little crazy

hybrid cross between "grow a pair of nuts" and "man up"

suck it up, just do it, who cares

(v.) To gird ones loins. Nutting up entails using one's proverbial balls or "nuts". Mainly used on the US west coast, it's the sister (brother?) term to cowboy up.

"Going crazy" or "manning up"

Verb phrase: To involve oneself in a physical altercation, to lose one's cool, or to fly off the handle. A common fixture of urban or "gangsta" vernacular. Recently popularized by a homophobic, black-clad drug-dealing NPC/pedestrian in the controversial PS2 game "Grand Theft Auto: San Andreas."

Losing one's ability to control excitement.