The sting lessens over time. U just have to learn the lesson and keep moving. Stagnation will ruin your mind, you will become a babbling retard if you don't put it behind you and try to get new experience to think about. You don't have to do big things to win this. For me, I was in a situation like this twice in my life. First time I felt very angry and sad, it took me 2 years to feel happy a bit again. And then I did some stuff like community service for government and I met some good people there. So it reminded me that there is some good funny people still, just don't get too close to them. Then second time I had some friends who were haters and used me and put me down a lot, I cut those guys off after years of talking, it was feel lonely for 3 months then it was easy to sit alone.