The phrase "haunts thoughts" implies a continuous preoccupation with a subject, idea, or memory. Antonyms to this could include "eases the mind," "brings peace," "cleanses the spirit," "soothes the soul," "calms the nerves," "relaxes the body," "allays fears," and "clears the head." These antonyms suggest relief from anxiety, worry, or distress. They evoke a sense of calmness, tranquility, and comfort. Instead of being overwhelmed by a persistent thought or haunting memory, one can find solace in the opposite feelings of serenity, relaxation, and peace of mind.