If someone has hurt you deeply,it can be easy to lose your temper (╰_╯)#to an extent.But forgiveness is possible-and it can be surprisely helpful to your physical and metal health .indeed,investgation has shown that people who forgive report more energy and better appetite and better sleep patterns ."people who forgive show less anger and more hopefulness ",says a famous man ,who wrote the book FORGIVE FOR GOOD."so it can be good for saving on the wear and tear on our system and allow people to feel more energetic."
  especially,in your own case ,you can't take it for granted easily.then what could you do !??_?
  Calm yourself down firstly.Take a couple of breaths and make every effort to  recall something that can cheer you up secendly .finally try to see things from the other people 'perspective,you may realize that what they do is reasonable to some extent,and a friendship may be made with him\her forever!!