Help finding the right CMS

Hi!

In my spare time around Christmas I developed a website with Visual Studio and published it with Firebase.

The site is starting to get some organic searches, only 50 per week, but still.

It’s just a hobby project, but I’d like to move from just writing HTML, Java and CSS to some kind of CMS.

I have a few small criteria:

• Maximum $10 per month
• Should be able to make automated lists of pages in a specific section (like the screenshot). That’s pretty much the main thing on my web. Section A has 500 pages, I use Javascript to automatically sort the pages under A, B, C etc. based on the first letter in the page title.
• Must be able to add custom HTML to text (such as FAQ schema markup)
• Must be able to add Google Adsense
• Fast loading times and good mobile responsiveness

Thanks in advance /vexxan