Stuck on the boat, blocks aren't dropping, chunks aren't loading, game won't save

I was trapped in a boat with a trunk, I had a lot of difficulty getting out of it and, after I got out, all the blocks I broke no longer dropped. Furthermore, chunk rendering has dropped a lot and every time I try to save the game it takes at least 10 minutes to save and close it (but, most of the time, it's not possible to save).