Optimize loading speed of my website -- 4

Hello, i need website loading speed optimization. Right now is very slow and i don't know why. It was done by other freelance team that did not know how to fix it.
I need an expert who can find out what is causing the slow loading speed for www.broomingboost.ocm and it's pages.

Pages load up to 7 seconds with is really bad

Compare these websties with mine
https://eloboss.net/
https://www.proboosting.net/

My website :
www.broomingboost.com

How can i have the same loading speed as other websites?