I have created a super simple plugin for me to add a simple separator with text and description, to separate sections, as you are asking
Sorry for the spanish pics, is the site im currectly working on.
This is the admin
http://prntscr.com/7poelo
This is how it look in edit post screen
http://prntscr.com/7poevw
And you can get it here
https://www.dropbox.com/s/ig49zhvejnkaqjg/acf-separator.zip?dl=0