Whenever I'm just running around in Minecraft, the game freezes and crashes randomly. I have taken to leaving my world and booting it up again every 5-10 minutes just to prevent the crashes. I usually play on Hardcore mode. Whenever I'm swimming up to the surface with 2 bubbles left and my game crashes, I'm drowning in the water while staring at a white "Minecraft (not responding)" screen. I just died on my 50th Hardcore Test (about 5'ish minutes prior to writing this) because I was in water (not deep enough to drown) and three skeletons were shooting me. My shield is up and next thing I know, my game freezes and crashes. I'm I suddenly hear what sounds like 5 shots hitting me at once. When I reloaded my game I was dead. If I can't find a solution to this problem then I probably won't be able to play Minecraft anymore without having to refresh every 5 minutes. 

The issues began in 1.15.2 where sometimes my game would crash and there'd be a zombie walking towards me. If I can't close out of the "not responding" minecraft tab quickly enough, the zombie can kill me. 
In 1.16.2, if my game crashes, ALL of my progress is reset to my last save point. Up until now, the same error that occurred in 1.15.2 occurred in 1.16.1 for the first time.