Lost my stuff in Minecraft?

I'm sorta an intermediate player when it comes to Minecraft. Anyway playing in survival mode, I had some good items in my backpack and was heading back to my base. I saw quite a deep cavern with some iron ore in it so I went down and mined. I wasn't planning to stay down there for long but then this witch came up behind me and killed me. I lost all my stuff and I didn't know exactly where I was when I died and I lost my map and compass in the process. I had to save & quit after that and so I just got back on. I finally found the cavern where I lost my stuff. Looking down from the surface I could see all my stuff and my experience orbs on the floor of the cavern. Once I made my way down all the stuff was gone? And I'm pretty sure I was in the exact place where I saw it like 2 minutes ago? Why did my stuff disappear and is it gone for good?

I think someone picked it up while you were gone

It is gone for good, and it is called despawning. Mojang or 4J studios depending console or pc has made a feature called despawning, it basically removes all the dropped items on the floor on the entire world to prevent lag. There's no way to disable it, only mods. Sorry to say…

Yes gabe is right items despawn after a while and thats some tough luck right there mate… Right when you saw the good stuff… Bam its gone lol happened to me like a bunch of times in minecraft >.>