I honestly kept clearing cache, repairing, had mods removed, but then tried removing save files, for a clean opening. I have everything backed up so I wasn't worried I'd lose anything. Once it opened successfully, I closed re-introduced my mod and save file folders then tried again.
I cannot say for sure "one" specific thing worked, more that, I just kept trying, repairing (I swear I repaired over a dozen times), clearing/removing files (to at try to at least open as a clean game), and restarting my computer till it worked. And I just bought this computer this year so it shouldn't be a hardware thing.
But for every time I removed a file folder or delete cache files, I'd do a repair just in case too. With a full PC restart every few tries.