I want to delete my community account

That's not as simple as it sound. Your account password here is also for your Apple Account (formerly Apple ID). If you delete that, your phone may not work correctly, if at all.

The better action is to email the moderation team and ask that all your posts here be deleted. That way, people can only see you nickname with no content or information associated with it.

The mods' email address is shown several time in the forum Terms of Use document here:

Apple Support Community Terms of Use

Specifically, A-13:

For questions or problems regarding your Apple Support Communities account, please post a question in Using Apple Support Communities, or email communityaccounts@apple.com.