Can't access backend anymore

Hi! Can anyone tell me what my problem could be? I was following this guide http://pointblankpro.com/how-properly-configure-w3-total-cache/ and got to the Minify part when I saved my settings. As soon as I did that, my site started to slow down and I started receiving the error 524 A timeout occurred (I’m using Cloudflare).

After that, I tried to access the backend again but with no luck. I tried a couple of times and got back in for a short time period so I disabled and uninstalled w3 Total Cache (even cleared out the configuration file and cache folders with the help of some guides) but the problem still persists.

I can go to the backend for a limited time, change a couple of things around but then “lose the connection” again. I even paused my Cloudflare for some time and tried to access the site this way but the connection timed out.

So, my question is, is this something w3 Total Cache could have caused and does someone know how to reverse it?

Thank you!

https://wordpress.org/plugins/w3-total-cache/