Om Swami
How do I stop hating someone who treats me badly or speaks ill of me?
Do not give your energy to the one you hate
Not everyone can become your friend, and everyone has critics. Whoever you keep thinking about, you are giving them your energy. Ask whether you really want to give your mind's and soul's energy and your tapas to that person.
Do you really want to give the energy and tapas (spiritual discipline) of your mind and soul to the person you are thinking about? We are giving them our energy.