KatelynCollins99 Do you have the codes for your Sims 3 discs? If so, and the base game disc was manufactured before September 2012, you can install entirely via disc without needing to use the EA App. You might need an external CD drive, but that's cheaper than buying the content again.
Only the base game date matters here, not the packs. So if your disc is too new, you could in theory find another used copy and install with that instead. The copyright year is in the fine print on the back of the case.
If your base game disc is new enough to force you to use Origin (now the EA App) to install the game, but you have the codes, you can contact EA customer support to try to figure out what happened to the account that owns this content. First, take a photo for the base game and each pack showing the disc, its case, and the product code (clearly readable). You can upload these when you submit the help request.
I would strongly suggest using the live chat option rather than email. If you don't see it, try this link:
https://help.ea.com/en/help-contact-us/?product=the-sims-3&topic=missing-game&category=manage-my-account&subcategory=find-missing-game
Make sure you're signed into an EA site (this one is fine) before clicking the link and that the location in the lower-right corner of the browser window is set to U.S. or U.K.
Alternately, try using the help site without being signed in. Some categories of issue allow you to proceed without an active login, and many of those offer the live chat option.
With no codes, your only option would be to try to login to the EA App with any other email address you had at the time and still have access to. Maybe you'll get lucky and find the account where you registered the content, and then you can download it.
As for Sims 4, that's just EA's policy, and there's nothing anyone can do about it.