spawning with nothing that i had and i did not die earlier and lost all of my diamond tools blocks items armor, just everything in my inventory but my pickaxe duplicated

i spawned in one f my friends worlds, not realms and when I spawned in i was right where i was when i left the game last time but this time i had nothing, none of my full set of diamond tools or any of my enchanted iron armor, none of my blocks or items, but i was right where i left the game, i didnt get killed or fallen in lava but i had my almost dead iron pickaxe had duplicated and then one of them disapeared when i tried to use it.