acrid, bitter, embittered, hard, rancorous, resentful, sore

disaffected, discontented, disgruntled, malcontentcontemptuous, cynical, disdainful, misanthropic, scornfulangry, cruel, harsh, irritated, mad, rough, savage, vehement, vicious, virulent, vitriolicacid, caustic, cutting, mordant, sarcastic, trenchantknock-down, drag-out(or knock-down-and-drag-out)

unbitter

caring, forgiving, gentle, kind, kindhearted, loving, sweet, sympathetic, tender, warm, warmhearted