Still trying to get into iCloud photos

I have been trying for more than three weeks to get into my Apple photos. I can get through all the steps until it comes to "Verify your email address". I have had an Apple account for over 10 years and have never changed my email address. When I type in the address and "continue", I always get the same red notice: "An unknown error has occurred" and I cannot get in. Does anyone have any suggestions? Thank you