In a somewhat similar situation I used PHP with `include`.

The structure was something like this:

  - index.php
  - header.php
  - sidebar.php
  - footer.php
  - page-1.php
  - page-2.php
  ...

In `header.php` I used variables for the title, description, etc. and then in each page I specified the values for those variables. This way each page had the same header HTML code, but with a different title, description and so on.