Resentment always happen to so called good people. Who deliberately never do anything wrong to anyone but sometimes in life feel that other person has done wrong with them. They are not able to give them back and this pain, feeling of injustice and anger remains in them as a resentment.
Universe will handle all. You need to handle yourself in this resentment. Get rid of it by doing whatever soothes you.
Or
take a professional help.
Hope this helps
