Find My Iphone not working on my Icloud?

Hello all.

I lost my phone today. So, I went on to iCloud.com/find to try and locate it. Log into this with my apple id and it says:

"Unable to load find Iphone,

your apple id: myname@email.com is unable to view this application. Please sign in with the Apple ID used on your device."

I used to have a different email as my apple id so I try to log into that. It then says my account is locked, so I go to unlock that account. When I try to do that it says this apple id does not exist/ isn't valid.

Help! Is there someway to fix this or get onto Find Iphone or is this a hopeless venture? Thanks in advance.