I went through a Nether portal and found some ancient debris and when I went back through the Nether portal I heard my player was taking damage. I noticed it took about 10 minutes to load the overworld and when it loaded I was dead. I then responded in the overworld and I tried to go through the Nether portal again and it wouldn't let me through after 5 minutes of trying. Finally, I made it to the Nether but my stuff was not there. It was a one-player world so no one could have taken it. So I lost 10 days of hard work  . This seems like a glitch that should be patched.