Bʟυɛ ♡
I'd make a separate folder and save all your assets in there. Make sub-folders inside separating different kinds of assets too. Then delete all your assets, and re insert them, one separate sub-folder at a time. Checking between each addition if the game crashes. Then you can locate the problem, if it doesn't already fix it. Otherwise just go back to basics and add some more essential ones and maybe shrink down your average assets folder size