Never really said how i feel?

just got news few minutes ago that a very closed friend left for another country.He told me that he is leaving but i did not expect it to be so soon.i,m feeling so bad bec he did call me last night but i was very busy i could not reach to my phone.we are very, concidered ourselfs as bestfriends but the thing that i feel bad about is that i never got to told him how i really feel about him.i have no contact with him now,he said he,ll leave all is info before he leave.i,m just wondering why he left so quick and if only i pick up my phone or if only i called back.i cannot explain myself.is there maybe another way to get hold of him