Can't change old e-mail on iCloud!

The e-mail adress on the iCloud reset, the one iCloud will send info on how to reset things if one forgets the passwords and such is an old one that I no longer have.

I tried changing it to the only e-mail adress I have but I keep getting a message that says that I can't use that e-mail adress as it is the same as the one connected to my Apple ID... I ONLY HAVE ONE E-MAIL and I'm not getting another one just for iCloud, what do I do?