Need help with bug laggs

[Th3is]

I have a huge problem with laggs:

99% of the time I leave a building, house, city, dungeon or what ever (example: building > skyrim, house > skyrim/> city, city > skyrim, dungeon > skyrim) my FPS drop from approximately 20 (what is normal and ok) to 3 or less and in menus like pause or map I have no FPS drops, but not when I go inside a house, etc. And when I go back inside the house or in another house the FPS are normal (city > skyrim > city in this case it won't work to go back), and the FPS aren't droping when I go to another instance of a house or dungeon. After restarting the game the FPS are normal untill I leave a instance.

 

I have tried a lot to fix it:

switch ENB off

install only basic mods

re-install skyrim

but non of these had worked.

 

I thank you in advance for any help and sorry for my bad english.