Calendar events disappeared; iCloud restore failed

I just opened my calendar and all my events are missing - i didn't delete anything or sync anything but all my calendar is gone except for bdays and public holidays which comes from the standard inbuilt info (not bdays i manually added). I have tried restoring from last icloud back but nothing changed. Have turned off and on and no change, i don't understand how it would just disappear? Please help it is my life line!