Item disappeared/Player Glitch

When I updated the game and I log into my world, all of my items were gone in my inventory. When I click on my nether chest to get some of my items to gear up, it was like I was a new player starting a new world since I couldn't see any of the old items I had inside. Please fix this issue, I do not know if it is possible to get back what I lost before this happened. Thank you and have a good remaining day. (I was using the same device when this occurred).