The antonyms for the word "upsetting" include calming, soothing, peaceful, comforting, reassuring, quieting, tranquilizing, relaxing, and pleasing. These words refer to emotions and feelings that are opposite to the ones caused by upsetting situations. Calming and soothing are used to describe actions that can reduce anxiety or agitation. Peaceful and comforting refer to surroundings or situations that offer a sense of security and harmony. Reassuring, quieting, and tranquillizing are used to describe words, actions, or medications that alleviate stress and tension. Finally, relaxing and pleasing refer to enjoyable activities that promote a feeling of happiness and contentment.