Is there a way to revert back to stage before changes were made in APM?

All,

I have made some changes to infrastruce setting in platform admin inside APM portal. The values that I changed are Direct GW server for application users server url AND local virtual GW server for application user url (only added port to 443). Since this change everything went south and I cannot access APM inside.

I ran the post install to find the correct hostname AND I type correct FQDN URL (LB URL) to access APM inside, but it kept saying "The HP Business Service Management URL must include the Fully Qualified Domain Name (FQDN). Please retype HP Business Service Management URL in the address bar."

What I am trying to do is to revert the changes back so that I can at least access APM portal inside. I am more than sure there are ways to do this which I am not aware of (revert it back outside of APM Portal). If anyone has ideas, please do let me know.

Thanks,