Game Won't Open with Working CC

I have had custom content and mods for years now, and my current computer is fairly new. For some reason whenever I download anything new it will not open the game at all. I have taken all my mods and cc out and added them back slowly, and it will randomly decide not to work. Files that I know for a fact were completely fine just a few days ago are suddenly causing the game not to load at all. I have reinstalled the game, redownloaded and updated my cc and mods, and tried clearing any caches I can. After a random point it just decides to stop working, and I have to start all over re-adding them. I have been losing my absolute mind over this so if anyone has any ideas whatsoever I would appreciate it. Thanks!!! :,)