V.

get the jitters; have the jitters; go into a tail-spin; go into a flat spin (Anglophile); feel alarm (ssn); fearmonger (Taras); go into panic mode (VLZ_58); make panic (Don't make panic! Soulbringer); overreact (Tiny Tony); be in a flap; flapping and fussing (Olga Fomicheva); flap (to become confused; to get into a panic • There is no need to flap); panic (to make or become so frightened that one loses the power to think clearly • He panicked at the sight of the audience)

get jittery (Don't get jittery Taras)

panic (= паникёрствовать); be stricken with panic (= паникёрствовать)

set one's hair on fire (Don't set your hair on fire over this. ART Vancouver); press the panic button (Taras); get butterflies in one's stomach (Irina Sorochinskaya)

have jitters (bigmaxus)

freak out (Woah, don't freak out, it's not the end of the world. dinchik%)); flap about; be stricken with panic