So you may have heard Bluehost enabled free SSL certificates for WordPress users on Shared plans and gone ahead and enabled it
But you ran into the same issue I had when adding your new fangled https:// enabled domain name into Google Webmasters Search Console
It just won’t take your new https://www.mysite.com domain name saying it’s already been added
Try adding an ending forward slash to your https://www.mysite.com domain instead
https://www.mysite.com becomes https://www.mysite.com/