Assessing what made the middle passage such a terrible ordeal for the enslaved africans?

Hey there! 
The Middle Passage was very hard and grueling for enslaved Africans.
To fit as many slaves as possible, they were loaded onto ships in very close quarters, meaning that disease spread, people got sick and died, and when that happened, nobody came to help. They would have to lie beside sick people, chained, and not be able to do anything.
This explains why it's such a terrible ordeal. And after they got to America, it was worse. They had a whole life in front of them of slavery.
Hope this helps!