Essays / Essay on Heraclitus for a monographic course in History of Ancient Philosophy [3]

Hello everyone, I found this forum while searching the web for tips about my essay on Heraclitus and I'd be grateful if one of you could help me.

I'm currently struggling with my first essay ever and I don't know how to put my topic down.
The course I have to write for is on the whole history of philosophy from Thales to Augustine, but my professor turned it into a monographic course on Heraclitus.

For the essay, I am supposed to support a thesis based on my knowledge of the said matter, but there are thousands of good topics worth writing about and really a few sites/books about the matter (as far as I know).

Main writing ideas are: the concept of fame/glory (κλέος) as said in the fragment 22 B 29 or the importance of Diels-Kranz's The Presocratics in the historical studies about philosphy.

My main concerns are: as for the first topic, there is not too much of informations while, as for the second, it seems a little off topic, to me at least.

I'd be glad if you could suggest me sites/books for my researches and give me some writing tips (how to structure the essay, things to avoid, opinions about the topics)!

Thank you!
PS. Excuse my mistakes, I wrote the best that I could, but english is not my first language, I'm Italian.