i logged back into my account and my sims 4 game is gone

Best thing would be to contact an EA game advisor about this issue.
You can do that through this link: https://help.ea.com/en/contact-us/
If you want to do so in a different language you can choose your country of choice in the upper right-hand corner. 

You can also choose to contact an EA game advisor through social media:
- Twitter: https://twitter.com/EAHelp
- Facebook: https://www.facebook.com/EAHelpHub/

I assume you've already tried these:

The game no longer shows up in Origin

Try the following things: 

• Restart Origin.
• Log out and back in and use the email address instead of the username. Make sure to use the one you used to register the game in the first place.
• Reinstall Origin.
• Restart your router/modem.
• Make sure the game isn't hidden by accident. To check, put the filter on Hidden Games. If it's there, right-click on the game to unhide ((click on the spoiler below to view an exemplary screenshot))
  
  Spoiler

  
• Get in touch with an EA Game Advisor.

Source: http://answers.ea.com/t5/The-Sims-4/FAQ-Serial-Codes-Game-Activation-and-Download-Issues/td-p/4228232