Our book list may have many title of interest to you.

Collapse of Ancient Rome

ten books

• R.A. Markus, Christianity in the Roman Empire
• R.A Markus, The End of Ancient Christianity
• P. Brown, The Rise of Western Christendom
• P. Brown, The World of Late Antiquity
• P. Rousseau, ed., A Companion to late Antiquity
• Averil Cameron, The Later Roman Empire (fourth century history)
• E. Gibbon, The Decline and Fall of the Roman Empire (not sure how "fact based" this 18th century, biased work is, but it is a classic and a masterpiece of scholarship that you should at least be aware of when approaching the "fall of Rome"). I'd check out the J.B Bury edition or the abridgment by D.M Low.
• G. Halsall. Barbarian Migrations and the Roman West, 376-568
• W. Goffart, Barbarians and Romans
• J. O’Donnell, The Ruin of the Roman Empire
• B. Ward-Perkins, The Fall of Rome and the End of Civilization

Removing for the wide breadth of request, and one of our moderators has pointed you to our book list.