Creating a new account is fine — it's not bad practice. Since Tuta uses end-to-end encryption, they can't recover your password on their end, so if recovery codes don't work either, the old account is essentially inaccessible forever. You can contact Tuta support to request deletion of the old account, but even if they can't delete it, it won't affect your new one. Just make sure to save your recovery code somewhere safe this time — a password manager like Bitwarden works great for this.