Dashboard very slow

My website address is gummeeusa.com. Whenever I do speed tests, my website scores pretty well, however the dashboard is very slow. I’ve tried deactivating all my plug ins, but it stays the same speed.

Here’s a list of the plug ins I have installed, just for fun.

Duplicator
Leverage Browser caching ninja
Ninja Forms
Responsive Menu
Simple Map
Woo Commerce
WP-DB Manager
Pingdom test: http://tools.pingdom.com/fpt/#!/WG0gy/gummeeusa.com

Google Speed Test: https://developers.google.com/speed/pagespeed/insights/?url=gummeeusa.com&tab=desktop

Does anyone have an idea of why my dashboard is so slow? I’ve updated it several times. I feel like I’ve tried everything! I’m pulling what remains of my hair out.

Thank you!