Fixing Google domain indexing issues + SEO rank stubbornly low

Site URL: https://www.beverlysiu.com

I have 2 problems which I think are related:

1. Google indexed my squarespace free domain for my site (ray-hibiscus-856y), which is odd because my site has been up on beverlysiu.com for more than a year through squarespace and was working correctly previously.
2. SEO ranking has fallen dramatically.

My site used to be the #1 result so I know it was working before. Both the wrong url getting indexed and the SEO issues were noticed at the same time. I tried requesting the google search console clear their cache but my request was denied. 

My only theory for why it might be failing is because I changed my template and my site now uses an index page for the home page, which afterwards I learned can hurt SEO ranking if one doesn't tell search engines not to index sub-pages (Squarespace why would you recommend this in your templates if you knew this would happen?!). My index page was empty though so that couldn't have been my problem. I've since done everything I could to optimize my SEO rankings (social images, meta descriptions, meta titles) but I'm still very low on google search and not even with my correct domain.

What is wrong and how can I fix it?

I can't verify for sure that the two are connected, as there was a big Google core update earlier this month that has caused a lot of changes. However, I can provide some guidance on how to resolve #1 and then you can see if that has any benefits for you.

So this is a common issue with Squarespace and they should provide a way in the admin to keep the built-in domain from being indexed. until then, follow the steps I've outlined here in this blog post and that will tell Google to remove your built-in domain from their index.

https://modsquare.io/blog/remove-squarespace-domain-google-search-results 

It may take a few weeks for this to take effect but it's worth a try.