Brutalizing, agonizing and dehumanizing parts of the enslavement process of the captured Africans?

From the text:

I had now some hopes of being delivered; for we had advanced but a little way before I discovered some people at a distance, on which I began to cry out for their assistance: but my cries had no other effect than to make them tie me faster and stop my mouth, and then they put me into a large sack. They also stopped my sister's mouth, and tied her hands; and in this manner we proceeded till we were out of the sight of these people.

When I looked round the ship too and saw a large furnace or copper boiling, and a multitude of black people of every description chained together, every one of their countenances expressing dejection and sorrow, I no longer doubted of my fate; and,
quite overpowered with horror and anguish, I fell motionless on the deck and fainted.

I was soon put down under the decks, and there I received such a salutation in my nostrils as I had never experienced in my life: so that, with the loathsomeness of the stench, and crying together, I became so sick and low that I was not able to cat, nor had I the least desire to taste any thing. I now wished for the last friend, death, to relieve me; but soon, to my grief, two of the white men offered me eatables; and, on my refusing to eat, one of them held me fast by the hands, and laid me across I think the windlass, and tied my feet, while the other flogged me severely.