Yes, JITTERS is a Scrabble word!

Letter values in Scrabble US: J 8, I 1, T 1, T 1, E 1, R 1, S 1.

Is it a valid word?

JITTERS is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

extreme nervousness
small rapid variations in a waveform resulting from fluctuations in the voltage supply or mechanical vibrations or other sources
a small irregular movement

Also: heebie-jeebies, screaming meemies.