Lost telephonenumber, password and a locked account

Hello,

my mother had an old iphone 8+, which she sent to my cousin, as she doesn't have a phone.

The account she used on the iphone was mine, To be clear, I still have access to the E-mail. Sadly, I don't have access to the telephonenumber anymore, or even remember the number itself. So when I try to reset the password, the recovery page asks me to verify the number, which I obviously can't. Also, for some reason, my account is locked. I can't even make sense of these endless E-mails.

Kindly,

heloux1112

[Edited by Moderator]