How can i integrate WordPress with GitHub without increasing load time of my website?

Hello,
I want to integrate My website: http://paintballmaskarena.com/ with GitHub but the problem is whenever I integrate my website the load time my website increases even some user cry about load time,
is there any solution to integrate my website without increasing load time.
Thank You.

Things I am using in my WordPress site.

  1. Generate Press Premium Without Page Builder
  2. wp rocket
  3. wp smush
  4. shortcode ultimate
  5. some security plugins like wordfence etc.