Custom content not working

Hello

I started up my sims the other day and for some reason all 400 items of my custom content that I spent hours downloading had disappeared. I'd been having trouble with it for a while because every time I tried to download a new item and put it into my mods folder, it never showed up in my game so I just continued with what I had. But now it was all gone. So I came out of my game and checked it was all still in my folder, and it was, but it wasn't transferring to the game. I wondered if it was because for some reason their file type had changed and was coming up as some sort of Adobe file I think. So I changed them back to package files and it still didn't work. I then thought maybe it was because my actual sims game was in the wrong place - it had downloaded into Sims 4/Game/Bin. I moved it, but it won't play in any other folder. I tried uninstalling and reinstalling the game but that didn't work either. My actual game is fine, but I can't get any custom content to show in the game, and I have since lost it all when I uninstalled the game. I'm not sure if it makes any difference, but my game is on a hard drive. I'm a uni student so I need all the space I can get on my laptop which is why I put it all onto a drive. Do you think this is the problem? Any help would be really appreciated, I find the game less interesting without custom content!