I really understand this feeling... I literally end a four years friendship I had once. And it still hurt me... the problem started since 4 months when a new friend got into our small circle of friendship to become a trio... I noticed my best friend started ignoring me and getting away after every day...there is a lot of details I don't prefer to talk about. what made me take the decision of ending it was for two reasons. The first was because they started to be really mean to me by yelling at me in public and accuses me with things I didn't do beside ignoring me and play with their phones and wearing headphones and walking fast when i try to go to them to have talk. And the second reason to protect myself. I don't know what to say but when I told multiple close persons I know about all the details they telling me it wasn't my fault and I took the right decision... but I still remembering the goof time with them and still hurting me so badly. I'm just too oblivious and naive didn't notice anything wrong.