@blossombcutie18 Hi,
If you interrupted the update process and now cannot select play, try the below:
First off, please make sure you start Origin with Administrator rights: http://help.ea.com/en/article/how-do-i-run-a-program-or-a-game-as-an-administrator/
Next please right-click the game tile under the "My Games" tab and select "Repair Game".
Are you able to progress now?
If you cannot, please re-start Origin with administrator rights then just right click the game tile and choose uninstall. Next download and install the game once more and report back here.
You will not have to purchase the game again. Your codes are associated with your account so just make sure you do login in to the same one you had initially registered your Sims 4 with.
Hope that clarifies that, let me know how you get on.
Cheers,
Nils