I have issues with my expansion packs, half of them dissapeared from launcher after I installed Into The Future and Ambtions expansion packs.
Before that everything was fine. I tried playing without the rest of my expantion packs and well, when i went back from the future my sim disseared and the sims i left in past I couldn't control.
@upsinubsi Playing a save without an expansion pack that was previously available in that save can corrupt the save, and the sims involved, so I hope you didn't save your progress, or you have backups. Adding the EPs back in later doesn't usually help. If you only saved once after losing the packs, the automatic backup should be from before those packs went missing; let me know if you need help recovering this backup.
For the missing packs, try repairing the game in Origin: open your game library, right-click on the Sims 3 icon, and select Repair. If that doesn't help, clear Origin's cache (you can try repairing again after), and if that doesn't help either, uninstall Origin "the hard way" and reinstall.
If none of this makes a difference, you can try uninstalling and reinstalling the missing packs. I don't know how you originally installed, but this is a common issue for people who have a mix of disc and digital installs: the disc-installed packs disappear after someone downloads a new pack through Origin. Reinstalling the missing packs can help, although it's more likely to work if you can download them through Origin as well.
The most thorough approach is to remove the pack-related entries from your computer's registry after uninstalling and be fore reinstalling. You can use a tool like Piriform's CCleaner (the free version is fine) or do it manually.