Does my feeling of hating people and their not accepting me, along with my loathing of family and relatives, without causing them harm, indicate a black spot in the heart, and how can I get rid of this feeling?

Love of isolation is not without one of two states: either it is without resentment towards people, or it is accompanied by resentment towards them. Resentment and hatred of people are signs of a sick heart, and the cure for that is trust in Allah, remembering people's good qualities, contemplating one's own faults, and accepting others and listening to their criticism.