I really have no idea why, but it's definitely loading very slow with good internet speed and good server speeds. It seems to be a script issue but no idea really. Please help :)

Actually site loads pretty fast for me. Please check the video: g.recordit.co/sTtN4zxsIb.gif

But it can always be optimized by using tools like: jotCache, JCH Optimization plugin. Please try, they are free and easy to manage.