It is possible to have just a single gallery displayed on a web page and switch the gallery (using links).
Check out the 'Switching between Multiple Galleries using JavaScript' example in the Embedding Multiple Galleries support section.
I've made a single-page template using this method and have posted it here (with instructions).
You could use/modify it to suit your own needs (or, at the very least, examine the code to see how it works).
If you are looking for a fully automated way to create and list multiple galleries, then you might like to look into another of our products: Showkase.
Showkase is a PHP web application (installed on your web server rather than your computer) which allows you to create a complete portfolio web site (integrating multiple galleries) online.
Showkase has full support for Juicebox-Pro and the galleries can be created within the application itself in a web browser interface (or created with JuiceboxBuilder or the Lightroom plugin and then imported via Showkase's 'Site -> Import' functionality).
You can create Gallery Index pages and have as many galleries listed on each Gallery Index page as you wish.
Each gallery is represented by a thumbnail image with the gallery title displayed below and the gallery is opened when the user clicks on the image (just like your current website).
Demo Sites created with Showkase can be found here and a sample Gallery Index Page can be found here.
Showkase can also create non-gallery pages (About, Basic and Contact pages) where you can add information about yourself (or any other content you like).
All of this is done automatically within the Showkase interface without the need for any manual coding at all.
You can take a look around the Showkase interface by logging into the Live Demo Admin.
Showkase can be purchased as Showkase-Standard (which comes with Juicebox-Lite, the free version) or Showkase-Pro (which comes with Juicebox-Pro) from the Download Page.
The only difference between Showkase-Standard and Showkase-Pro is the bundled viewer (Juicebox-Lite vs Juicebox-Pro).
If you already have Juicebox-Pro, then you could purchase Showkase-Standard (if you wanted to) and integrate your Juicebox-Pro files by following the 'Installing Juicebox-Pro' instructions here.
I hope this information is helpful.