Brave New World by Aldous Huxley: Section 4

It is rant time for Brave New World by Aldous Huxley. Up until the last chapter of this novel I thought the book was great. Midway through when Bernard's life went downhill, I began to see this book was not what I thought it would be. Then once John had the discussion with the Controller, I began to have new hopes for this novel. Sadly, once John hit the island, I began to experience confusion. I do not understand the relevance of John, "picking[ing] up the whip and [then he] began hitting himself again" (Huxley 248). I understand that punishment and forgiveness from God involves inflicting pain on oneself in John's religion. What I do not understand is why he does this multiple times and the civilized people freak out. That is literally the main point of the last chapter. I find it to be extremely random. I also do not understand why he hangs himself after he wakes up in the morning. Did he whip himself or Lenina? I thought that he whipped himself, so I do not understand why he would just decide to kill himself for something he had already done before. If I were to come up with any explanation for this I would have to guess that he might have hanged himself because he did as the crowd instructed him? This ending angered me a great deal, and caused me to think poorly of the novel.