agonizing

insufferable, insupportable, intolerable, unacceptable, unbearable, unendurable, unsupportable

appalling, awful, bad, dire, dreadful, ghastly, horrible, miserable, nasty, rotten, severe, terrible, vile, wretched

acute, extreme, intense, piercing

acute, exquisite, extreme, fierce, intense, vehement, violent

biting, cutting, penetrating, piercing, sharp, shooting, smarting, stabbing, stinging, tearing, tingling

assailing, attacking

badgering, dogging, hounding, pursuing, riding

aggravating, agitating, annoying, bothering, bugging, chafing, distressing, disturbing, exasperating, galling, getting, grating, griping, hagriding, harassing, harrying, irking, irritating, molesting, nettling, peeving, pestering, piquing, putting out, rasping, riling, vexing

discomforting, discomposing, disquieting, flustering, grieving, perturbing, straining, stressing, troubling, trying, upsetting, worrying

crushing, oppressing, overpowering, overwhelming, smiting, striking, tyrannizing, victimizing

hurting, paining, panging, pricking, smarting, stabbing, stinging, wringing

martyring

aching, longing (for), pining (away), sighing, smarting

racking, tormenting, torturing

bemoaning, bewailing, deploring, lamenting, ruing

bawling, blubbering, crying, groaning, howling, keening, moaning, sobbing, taking on, wailing, weeping, yammering, yowling

languishing

regretting