I don’t suppose the specific adjective you’re looking for happens to be querulous, is it?
Per the OED, it means:
Complaining, given to complaining, full of complaints, peevish.
Another possibility might be belligerent, which was originally from the Latin for war-making, but now more often means simply combative in a more general sense. There’s also bellicose, which may now carry additional connotations of loudness.
You can find synonyms to these at the links given above. Surely one of those must be your sought-after word. The merged set of suggestions provided by those two links is:
aggressive, antagonistic, ardent, argumentative, at loggerheads, battling, bearish,
bellicose, bemoaning, cantankerous, captious, carping,
censorious, combative, complaining, contentious, critical, cross, crying,
deploring, discontented, dissatisfied, edgy, fault-finding, fierce,
fighting, flip, fretful, grouchy, grousing, grumbling, grumbly, hard to please, have a bone
to pick, have chip on shoulder, have it in for, hostile, hot, hot-tempered,
huffy, irascible, irritable, lamenting, mean, militant, nasty, on the outs, ornery,
out of sorts, peevish, petulant, plaintive, pugnacious, quarrelsome,
scrappy, scrappy, snappy, sour, testy, thin-skinned touchy, truculent,
uptight, wailing, warlike, waspish, waspy, whimpering, whining, whiny.