Correct use of headings tags

Ok, thank you a lot!
So let’s say that I have this article structure:

intro text

prologue (current h3)
text
heading a (current h2)
text
heading b (current h2)
text
epilogue (current h3)
text

In this case, would be best for me to remove the h3 tags and use a simple bold text, instead, for those prologue and epilogue?