Items disappearing when dying in nether portal

I entered my nether portal while in the nether. While going through the portal a magma cube also travelled through my portal. When I arrived in the overworld I immediately died as a result of the magma cube. I respawned in my house which is nearby the portal, and went back to retrieve my items immediately. However, when I went back, they were nowhere to be found. I went back into the nether figuring that they may be there but they were also not there. So as a result I lost a lot of valuable loot and items that just magically disappeared. This bug is very frustrating because I lost a lot of progress by no real fault of my own.