Site slow help

Hi im not sure where to post this but i would like some help.

My site is running so slow and ive tried loads of diffrent themes and removing plugins so i dont know if its the site or the host and not sure how to tell. Ive tried to contact who im with and i think there a reseller using heart.ltd uk. I have had site with this person before and i have another on that seems fine but this new one is bad and no matter what i do i cant find the problem.
Can some one help as i dont want to move it if its not the host and it is the site.

Thank You
https://www.theworksopblog.co.uk