Site is completely down after installing cloudflare

My site is completely down, homepage is giving 404 error. Other pages are displaying error messages accross the board with loading issues and all sorts.

Can anyone help me through the problems and how to begin sorting out this mess?

You posted an HTTPS link, did your site work on HTTPS before Cloudflare?

yes no problem, I think I got it back now, removed a few plugins and some of the cloudflare settings.