u/Expensive_Ant8284

I'm having a weird problem I've never seen. My graphics in the launcher is Ultra, however every time I play Skyrim it's so slow even though the launcher detected Ultra Graphics. Because the game runs slow I had to get rid of my graphic mods but it's still a problem for me everytime I play. So I tried changing the graphics in the launcher and when I stafrt the game and start a new game I get a CTD and this error from the crash logger:
Unhandled exception "EXCEPTION_ACCESS_VIOLATION" at 0x7FF67C3C6440 SkyrimSE.exe+0646440 or [rax], al

Can anyone please help me?