I changed my email address and now my games are missing on the My Games tab. I'm running on Windows 7. Does anyone know what to do?

Did you change it through the site? Origin - my account - basic information - edit? Did you create a new Origin account?

Yes.  I did change it through Origin with the change account action.  I don't think I created a new account because I've also tried my old login and it no longer works.

You need to contact a Customer Support game advisor for this

Game advisors can be found through live chat.

1. https://help.ea.com/en/contact-us/ 
2. Set your language to US at the bottom
3. Click on Contact a game advisor 
4. Describe your issue with a few words
5. Click on Find a Solution
6. Select Product: ex: The Sims 3 or Origin
7. Select Issue Type: ex: Billing/Purchasing or Account Management
8. Select Platform: PC
9. Click Find solution
10. Scroll down and click I still need help
11. Click Chat Now to chat with a Game Advisor
    

With Pics here: http://sims3.crinrict.com/en/2012/10/how-to-contact-ea.html