Deleted email address Nintendo account verification code?

Hello,

I need some help. My Nintendo account is managed by my older brother's email address. I've purchased a lot of games on this account, and I've made a lot of progress on the games I've played. The problem is, my older brother's email address no longer exists, or rather, he's deleted it. I can still play on my Switch using this account, but to log in, I need a confirmation code sent to the email address. Am I just unlucky? Are there any tricks, or can this be resolved somehow with Nintendo? It would be a real shame if all the money and all the progress were lost. Thanks in advance for the help!