I understand that ancient warfare worked very differently than in the movies, with armies holding lines and trying to break the enemy line or flank.
But as for cavalry, I have a hard time imagining heavy cavalry charging at full speed. What was a clash between two cavalry armies like? It sounds like a deadly thing to do and a sure way to end up falling off your horse and breaking your neck.
What happened after a cavalry charge, did the cavalrymen get to the other side of the formation or did they stop first? Both seem strange to me, if they got to the other side they would be left with an army on their back, and if they stopped before they would have a bunch of enemies in their way that could pull them off the horse. How did they keep the line in front?
Can I consult any video or literary material that is realistic in this regard?
You might be interested in some earlier discussions on this. Especially this thread by our u/Hergrim vividly describes the experience of a knightly cavalry charge. That thread has also been discussed more by Hergrim himself and u/ParallelPain (here) and by u/Iphikrates (here).
Furthermore, the details of cavalry combat also been discussed by military historian Bret Devereaux on his blog here and here, using Lord of the Rings as an example