Remove duplicates of specific line keeping only the first appearance of each without touching other unspecified duplicates

I'm trying to edit a text file containing several duplicates. The goal is to keep only the first match of a string and remove the rest duplicate lines of the same string. In the example file

* Title 1
** Subtitle 01
#+begin_src
  Line 001
  Line 002
#+end_src

* Title 1
** Subtitle 02
#+begin_src
  Line 001
  Line 002
#+end_src

* Title 2
** Subtitle 01
#+begin_src
  Line 001
  Line 002
#+end_src

* Title 2
** Subtitle 02
#+begin_src
  Line 001
  Line 002
#+end_src

I'd like to keep one of each

* Title N

and *keep all other unrelated/unspecified duplicate lines* on the file. So the result would be:

* Title 1
** Subtitle 01
#+begin_src
  Line 001
  Line 002
#+end_src

** Subtitle 02
#+begin_src
  Line 001
  Line 002
#+end_src

* Title 2
** Subtitle 01
#+begin_src
  Line 001
  Line 002
#+end_src

** Subtitle 02
#+begin_src
  Line 001
  Line 002
#+end_src

The traditional solutions for removing duplicates like

uniq file.txt

[Useful AWK One-Liners to Keep Handy](https://linoxide.com/useful-awk-one-liners-to-keep-handy/) :

awk '!a[$0]++' contents.txt

[shell - How to delete duplicate lines in a file without sorting it in Unix - Stack Overflow](https://stackoverflow.com/questions/1444406/how-to-delete-duplicate-lines-in-a-file-without-sorting-it-in-unix/32513573#32513573)

perl -ne 'print if ! $x{$_}++' file

delete every duplicate indiscriminately. I tried using variations of these solutions and also GNU

in a loop format like

duplicateLines=$(grep -E "^\* .*" file.org | uniq)
  printf '%s\n' "$duplicateLines" | while read -r line; do
  sed "s/$line//g2" file.org
done

with no success. I don't mind absolute performance so doing multiple iterations like calling

inside a loop to remove one specified string at a time is no problem. Any insight would be very much appreciated. It would be nice to be able to do this inside a shell script but I'm open to alternative solutions like Python, C, Java, etc., just tell me what the function/library name is and I'm searching for it there. Thanks.