OK
Then try these steps (as said, at your own risk but the worst that can happen is that you will need to reinstall anyways)
Be aware that your saves also might not work if you saved a game with an expansion that is no longer present
- Backup your user files: http://sims4.crinrict.com/en/2014/09/backups/
- Make sure you turn off automatic updates in Origin (or your expansions will just reinstall on their own)
- Go to this folder: programs(x86)\Origin_Games\thesims4 (path may vary depending on your installation) and programs(x86)\Origin_Games\thesims4\delta
- Delete the folders of the EP/SP you want to remove. (EP = Expansions, GP = Game Pack, SP = Stuff Packs, FP = The XMas Free pack). They are numbered by release order