PageSpeed Insights - Speed Index

The speed index on my pages is awful when I check on mobile, however, on desktop, it's pretty decent. All of my pages are optimized for best practices and SEO however, I am struggling with performance metrics. Can anyone advise me on what to do to improve that? 

Squarespace is known to not test very well on Google speed index. There are things you can correct (such as image size), but many of the "issues" are to do with how Squarespace is set up and how these tests work, it tends not to reflect on how your page actually loads.

Overall I wouldn't worry too much unless you are experiencing your page loading slowly.

Thank you for the reply, appreciate it!