Can use a different email address for different forms instead of my registered email?

If I understood you correctly, you want to use different email address as Recipient Emails of email Notifications in different forms. 

Yes you can use different email address. All you need to do is to set different email address as Recipient email inside of your form Notification. 

Inside of this guide you can find how to set up email Notification:

http://www.jotform.com/help/25-Setting-Up-Email-Notifications 

In case that you want to sent Notification to multiple recipients, please check this guide: 

http://www.jotform.com/help/39-Send-Notifications-to-Multiple-Recipients 

How to properly Change and Test a New Email Recipient Address:

http://www.jotform.com/help/314-How-to-properly-Change-and-Test-a-New-Email-Recipient-Address- 

Hope this will help. Let us know if you need further assistance.