@MahouSims -
I think it's very interesting that you can connect & log in to the gallery online, but not through the game. Did you try marking anything to download? Just wondering what happens if you try to add something to your gallery from there. Make sure you're using an adult account - just in case this account was made as an underage account back in the day, and you haven't changed it since leaving home. Underage accounts cannot access the gallery.
Since you can't immediately test elsewhere, there are a few other things you can try. First, very important - If you have any mods or cc, completely move them all to your desktop or an external hard drive. Then copy your save folder to the desktop or external drive, as a backup. That way, if anything gets worse or lose something in-game, you have a way to get it back.
Once you've removed any mods and cc, and backed up your saves, here are a couple of thoughts on things to try:
- Clear the cache files (@crinrict has an easy to understand how-to here: https://sims4.crinrict.com/en/2014/09/delete-cache-files/)
- Repair the game after clearing the cache (I know you did it already, but try again)
- Set Origin and The Sims 4 shortcuts to "run as Administrator".
- Make sure Origin itself is online (Origin menu - Go online)
- If none of those works, you might want to contact the tech support / administrator of your school's wifi and ask if there are any blocks that would prevent you from accessing the gallery.
Please let us know the results - Happy Simming. 🤞