Dedicated Server Response Time - Need To Improve

So I decided to use HB's optimization tools to improve our performance score. I followed the tut on how to do things like placing custom CSS in ASSET OPTIMIZATION/Tools and then moving all of the style.css's to the footer, that kind of just broke everything, so I went back and undid that one. Otherwise, I disabled some CSS and some .js and compressed some other, my performance score was 80 at the beginning and now is 68...
Yep, screwed that all up.
So I was trying to run some PSI and suddenly there was no information on my site so I had to use LightHouse in Chrome Dev Tools and I found it saying that my root document took 1,911 ms to get the first byte!

That's insane we have a dedicated at HG for this client and there is NOT a lot of traffic on the server, shouldn't we be rolling better times than that?

Does anyone know if there is something I can do in WHM to give this account maximum resources availability? Not sure how to ask that question, I want this one to like be the Dev's Pet.

Thanks, for any ideas or criticism!

PS, most current WP and Divi with primarily WPMUDEV plugins. Weglot translation, Child Theme, left the backdoor open if you need a look.