Missing dlc
In the EA App, click The Sims 4 game tile and go to Manage Game-> Manage Add-Ons. Are you seeing your DLC in the list there to install, or is your game library showing as empty in the app?
If it's showing as empty, there's a chance you're logging into the app using the wrong EA account. You'd need to login using the same account you purchased all your content on, and you'll see everything available to download and play again.
I'd recommend checking any emails you have for the email receipt of these purchases so you know which account to login to the app to. If you need further help locating the correct login details, that's something live support can help with- you can reach out to live support by submitting a help request here, or you can get in touch with that team via Twitter or Facebook as well.
