my heart hurts

In my head, with the information I have been given, I know it's not meant to be.  But in my heart, it was never meant to end.  Tears come in waves, not all at once.  For the first few days I think I felt relief, a weight off my shoulders, because what had been weighing on me was done.  Then time passed and I was busy with things, and then it hit me and I was flooded with immeasurable sorrow.  I was OK after a day or two, and then went back to being busy with things and distracting my focus.  I thought maybe it was over.  But now, I feel the tears washing over me again.  Part of me wants to crawl into a cave and hold myself tightly in a ball until the world around me disappears, until maybe I disappear.  Not forever, just maybe until all this goes away, until all is right with the world again.  Because all does not feel right with the world.  I don't have people that I talk to about these things.  He was the person I talked to - about everything.  Other friends don't seem available when I need them.  The worst thing ever is to give someone a call and reach voicemail or have them answer and say they're busy and then never get back to me.  It makes me not even want to try sometimes.  I know that this is just a breakup, and I did the breaking up, and we parted on good terms, are still friends, but I feel like what we had is lost.  I feel like my best friend died, and like I killed him.