I'm sorry to hear that you've lost your login information after resetting your default keychain. Unfortunately, it is not possible to restore the information that was saved in your keychain unless you have a backup of that information. If you do have a backup, you can restore your keychain by following these steps:
- Open Keychain Access, which is located in the Utilities folder in your Applications folder.
- From the File menu, choose "Import Items."
- Select the backup file that you want to use, and then click "Open."
- Enter the password for the backup file, if prompted.
- The items in the backup file will be added to your keychain.
If you do not have a backup of your keychain, there is no way to restore the information that was saved in it. In this case, you will need to manually re-enter the login information for all of your accounts. I apologize for the inconvenience.