Transferring Theme to Correct HomePage

I have a website that was built manually years ago with html and css and hosted by Bluehost. Lets call it abc.com (not real).

I purchased the HighEnd theme to revamp the website, and somehow it was installed as the homepage being abc.com/abc instead of abc.com

I’ve spent hours and hours developing on abc.com/abc before I realized the issue. Every child page off the homepage had urls like this: abc.com/abc/childpage

What I need is to transfer all the work I’ve done on abc.com/abc to the correct site of abc.com … I know in WordPress settings there is a way to change the WordPress address and the Site Address, but whenever I change these it completely messes up my site to the point where I can’t even log in until the host changes it back.

Is there something I can do to apply the theme and all my created pages to the correct site of abc.com?