When i defeat the ended dragon I went and got the elytra and dragon head and when I jumpy in the portal to get to the over world it killed me and all my stuff was gone

When i defeat the ended dragon I went and got the elytra and dragon head And when I jumped back it the portal to go to the overworks it killed me and all my stuff just disappears and my screen was frozen I was just hoping to get my elitra and my diamond pickaxe and my dragon head back pls