1. You try email routing provided by cloudflare.
2. It does not work for you
3. Somehow you get your DNS into an odd state. email routing is disabled because it is misconfigured.
4. You cannot delete your dkim record without first disabling email routing.
5. You cannot disable email routing because it is already disabled because it is misconfigured!!
6. Cloudflare only allow "guided" support for free accounts, and guides you to /dev/null for attempting this kind of problem.