The antonyms for the phrase "broke one heart" are "mended one heart," "healed one heart," "comforted one heart," "soothed one heart," and "repaired one heart." These words describe actions of love, care, and nurture towards someone whose heart has been broken. When we mend someone's heart, we bring it back to its original state, and when we comfort and soothe one's heart, we help them get over the pain they are experiencing. Healing someone's heart takes time, effort, and patience, but it is worth it. Thus, it is essential to treat others with kindness and empathy, and endeavor to mend their broken hearts with love and care.