The Sims 4: Get To Work Expansion Pack Won't Install!!

So, after looking around some more, I've managed to solve my own question. 

For those of you with the same problems, my solution is below:

After snooping around on the Sims 4 forums, someone suggested to just go through Origin by opening the Origin window, clicking "Origin" at the top bar, click "Redeem Product Code" and enter your GTW product code.

Afterwards, it will do nothing. This is the part that freaked me out. Don't freak out - it'll be ok.

Because Get To Work is an expansion pack, it won't show up in your Origin library and won't even show that its downloading. Instead, you have open The Sims 4 and click the Plumbobs button on the tippy-top of the opening page, and there is where you will see that you "own" the GTW expansion pack.

As for what happens after that, I don't know. Mine is still downloading so I can't say at this time.