Everytime I launch my main world Minecraft crashes

Every time I load my world Minecraft crashes and I've tried turning off multiplayer, lowering all the settings, resetting the switch, turning off the internet,making a copy of the world and launching that too. Prior to that  I was getting not fps lag but I would talk to a villager and it would take 30/45 seconds for the trade window to appear. Similar to ringing the bell, mining, and hostile mob. I'm afraid I might lose my world and I would love all advice for a possible solution! Apologies for the terrible formatting and incorrect info because it does not display correctly for me on my phone.