before happening this error i go to the general setting and on the place of HTTP i did HTTPS by mistake. but now i am unable to login into my wp-admin panel

Whenever i type www.mydomain.com/wp-admin/ the privacy error comes:

Your connection is not private

Attackers might be trying to steal your information from
www.mydomain.com (for example, passwords, messages, or credit cards).
Learn more NET::ERR_CERT_COMMON_NAME_INVALID

Automatically send some system information and page content to
Google to help detect dangerous apps and sites. Privacy policy

How can i fix this problem?