Irascible

i-ras-cib-le (-rs-bl, -rs-)

adjective
1. Prone to or easily provoked to outbursts of anger.
My ex-lover died, my roommate moved out, I have no money, my daughter is moving out, my sister disowned me and I've been on hold for half an hour; forgive me if I seem a little irascible.
2. Characterized by or resulting from anger.
“Imperious, choleric, irascible, extreme in everything, with a dissolute imagination the like of which has never been seen, atheistic to the point of fanaticism, there you have me in a nutshell, and kill me again or take me as I am, for I shall not change.” - Marquis de Sade*

Synonyms: acerbic, angry, antagonized, bearish, belligerent, bitchy, bitter, bristly, cantankerous, caustic, censorious, crabbed, crabby, cranky, cranky, churlish, cross, choleric, cross, feisty, ferocious, fierce, fiery, fractious, fuming, furious, galled, grouchy, hasty, hot-tempered, huffy, ireful, irritable, ogre, passionate, peevish, petulant, querulous, quick-tempered, short-tempered, snappish, surly, testy, thin-skinned, touchy, uptight, vexed, wrathful.

* The Marquis' name provides the origin of the modern term sadism.
** The image is a depiction of the Marquis de Sade by H. Biberstein in L'Œuvre du marquis de Sade, Guillaume Apollinaire (Edit.), Bibliothèque des Curieux, Paris, 1912.