Best hosting for my condition…

I have around 4 sites running on the 6 core plan of host gator cloud. It was doing well, but I update 2 of my wp site’s regularly and one of them have 3k pages and the other has around 1.5k pages. The speed has been super slow lately and I’m pretty sure it’s because of how much pages I have on the site. Not sure if I should move to a better host… if yes suggest me some or hire someone to optimize my site.