Why does sending Metta to someone who hurt me result in emotional numbness and shutdown?

Namaste Aditya. "Numbness" is not the absence of feeling; it is the Overload of Feeling. Born March 30, 1993, in Kolkata, your chart shows a Scorpio/Moon or a strong Pluto influence. You feel things "too much," so your brain has created an "Aura-Breaker"—a complete shutdown to prevent you from being destroyed by the pain. Your heart is blank because it is in "Protective Hibernation." Forcing Metta (love) on the person who hurt you is like trying to put a 2000-watt bulb in a socket that has already blown a fuse. Detailed Solution: Stop the Metta toward that person. It is counter-productive. The New Path: Practice Metta toward a Tree or a Pet. Your heart needs to remember how to "Feel" in a "Low-Stakes" environment first. Indifference is not "Depression" in your case; it is "Conservation of Energy." Detailed Remedies: Remedy: Spend time in nature. The "Green Energy" of trees naturally repairs the "Numbness" of the heart. Stone: Hold a piece of Malachite; it is the "Midwife of Emotions" and will help the heart thaw slowly. Mantra: Chant "Om Namah Shivaya". Shiva is the lord of "Numbness and Stillness"; he will hold the space while you heal.