Doing headings in the Bible really takes a bit of fine tuning of formatting.
For the kind of fine tuning I've done in the Maori Bible, in parrticular Psa 119 you will notice that when there is another heading, there is a paragraph break with no text from the above verse to the next verse (go to the Maori Bible Download page and click on the image to see the example).
With regard to the Psalms which have an introduction, I placed a demarcation between the intro and the main text by having placed an empty paragraph. This really tidies up the formating and makes readability flow more easily.
If you have the LEB with notes, you will notice it too shows a clear paragraph between the last verse of a paragraph and the heading of the next paragraph.
Just thought I'd share some thoughts regarding the formatting done, and trust it will prove to be of some benefit to you.