High End PC Loading Slowly

Hi, My computer is fairly new (built it last summer) and high end (1080Ti, 16GB DDR4 ram etc.), yet as of late (past 2 days) when loading INTO game my computer has been freezing randomly (load up to 43%, freezes and stops working, then up to 76%, freezes again) and I can barely get into game.

Then when I finally get into game my screen is black. It took about a minute for the black screen to change to the map, at which point I had ~15FPS. I ended all league tasks and relaunched on admin, and on second launch everything went smoothly and I entered game quickly w/ 144FPS. Relaunching DURING loading and running on admin doesn't fix the problem, only once I've fully loaded in @ the 15FPS.

The end game pan to nexus also freezes the game.

This glitch has happened for about 10 games and I can't think of anything that changed to cause it. Anyone have any ideas?

Dunno if this is the right board, also submitted a support ticket.

Thanks!