Don't panic! This is a very simple (and common) issue with a very quick resolution.
Your POAP is no longer visible because you still have the POAP Scanner, or the POAP app (iOS/Android), set to check your email address for your POAP collection. Now that you minted your POAPs to an Ethereum address, they are no longer being reserved by your email address and, therefore, are not showing up.
In the case of the POAP Scanner, either: (1) connect your wallet directly, or (2) manually enter your Ethereum address/ENS name.
If using the app, you'll instead need to click on the settings icon in the bottom-right and tap "Forget account."
On the following page, you'll be asked to enter an email address or Ethereum address to view your collection. Where previously the app was directed at your email address, now you want it to view your Ethereum address.
🎉 That's it! Now you should be able to view your POAP collection. 🎉