Issues with account I don't want and the one that I do

This is not my account! I have a reddit account which has been blocked due to a 'potential security risk' but whenever I try to do anything about this, it defaults to this account which is not mine and is not an account that I want. I suspect it was created when I tried to use an email function as when I originally loaded the reddit app, I didn't add my email address. Yes, I'm a bit old and stupid.

So, what do I do now? I have tried to delete this account and it won't go!