Save file won’t load – Sims freeze on load screen

Hi,
I’m having a serious issue with one of my save files in The Sims 4.

Whenever I try to load my main household, the game freezes on the loading screen — the plumbob spins, but nothing ever loads. I've waited 10+ minutes and it just stays stuck. This is what i've already tried:

Removed all mods and cleared the cache (localthumbcache.package deleted)
Tried to load older autosave versions of the same file (e.g., ver0, ver1)
Created a new save — it works fine, but it doesn't include the progress from my original save, which is very important to me
I did not install any new mods or content since the last time the game worked

And also what's important:

The save file itself doesn’t seem corrupted structurally — I’ve had someone check the file header and it looks valid (FBPD signature is present, non-zero content)
I can open the game, access Gallery, and create new saves — only this household/save file won't load

I’ve backed up the save file just in case. Is there any way to repair it or extract the household and lot with their full progress (skills, relationships, etc.)?

Thanks in advance for any help or suggestions.