Not a problem, and the account is not lost.
If you have not confirmed the wrong address yet, just go back to Settings → Email and enter the correct one. The unconfirmed address is discarded.
If you already confirmed the wrong address, contact info@finoha.net from the correct address and include your account ID (Settings → Your account ID). That ID is what lets us find your account without needing the email at all, which is exactly the situation it exists for.
Do not create a second account to work around it — your progress and any subscription stay on the first one, and having two makes it harder to merge, not easier.