I had an idea, try it out: Find and replace with regex:
find → (.[asterisk]\n.[asterisk]\n.[asterisk])(\n)
replace → $1#$2

then split by: #

(I had to write [asterisk] because 2 * makes it italic
so just substitute [asterisk] by *)
(the find will search for a set of 3 paragraphs, and insert a # after these 3 paragraphs)
(you can use another symbol if you want, ex: §§§ (and split by §§§)