This issue is not Cloudflare related but something on your origin. The site is equally unresponsive when going directly to your server
$ time curl -I --resolve naijacenter.com:443:IP https://naijacenter.com
HTTP/1.1 200 OK
Content-Type: text/html; charset=UTF-8
Last-Modified: Sat, 06 Jun 2020 23:00:35 GMT
If you say this stops when you point your domain back to your host, my best guess would be your site is trying to connect to itself via a proxied record and runs into its own timeout. That would also explain why the site takes 101 seconds to load, which indicates either the default Cloudflare timeout or something similar.
Cloudflare might be passively involved, but the issue itself is not Cloudflare related. Thats something you need to debug and fix on your server I am afraid.