I solved the problem, I think. Turns out it was a (corrupted?) mod file, virus maybe? The mod is called Diplomacy Values (BNW). Here's where it gets weird, and ominous of a virus. I didn't have it turned on, I didn't even have it in the MODS folder, it was in a MODSBACKUP folder I used to make sure my mods aren't deleted from the offline "glitch", where the game deletes mods you had installed sometimes after putting Steam in offline mode.
This mod appears to bloat my games with "empty" data, and cause critical errors, infinite loads, ect even when not turned on or in the mod folder. When I reinstalled, and when I even tried the other PC, I coincidentally opted to DL all my mods, while keeping them turned off, because I assumed the issue wouldn't be mod related if they were turned the hell off.
Only after I took my friends advice in moving all mods out of the Civ V folders and sub folders, did I notice it was gone, so I tried every mod, one at a time and sure enough this is the mod that appears to be causing it, I even deleted and redownloaded, and it still did it. I don't know if the mod has a virus or what, but now I have to give up one of my favorite mods.
I'm still in the "testing" phase of deciding whether this is the culprit, but I'm on day FOUR of the same saved game with no issues yet, prior to this, I was lucky to get a few hours in before problems occurred. This also explains why when I played a Vanilla game, and saved it, then loaded, it always crashed, just like how when you try loading a modded game in the vanilla load screen.
I don't know what to make of this, I even scanned it with AVG/Malwarebytes, nothing. I'm stumped. Thank you all for trying to help, I'll update this on Sunday after a weeks of play, if it works still then, it's pretty certain I've found the culprit, even if it doesn't make any damn sense.