Severe stuttering - should I start a new game?

[WhatRules]

When I start playing everything is fine, but after reloading or changing cells the game start stuttering so much that it becomes unplayable. I checked the papyrus log and there are so many errors that I can't explain, like the game looking for mods that I've never installed or aren't required in my game.

 

This line is particularly worrying:

"Suspended stack count is over our warning threshold, dumping stacks" which means the game tries to do too many things at once and has to discard scripts at random. Is there no way to repair this save?

 

Papyrus.0.log