The game crashed when I enter the nether, and when I reload my world, it says that I died and when I respawn all my stuff is gone

When I enter the nether, after about 5 minutes, the game will crash. When reopening Minecraft, it works fine, but when I join the world it will save the location of where I was, but not the blocks broken. For example, I was mining in the nether, it crashed, I rejoined the world and it said I suffocated. When I looked for the items that were in my inventory, I couldn't find them. I even created a copy in creative and searched but still couldn't find them. It had been less than 5 minutes so the items didn't despawn.