And Ahithophel said unto Absalom (2Samuel 17)

So, there's not much in 2Samuel chapter 17 so I'll make it short. Ahithophel suggests a battle plan to take down David. Absalom wants to hear what Hushai thinks, and Hushai suggests a different plan. Everyone likes Hushai's plan better, supposedly because it's God's will for Ahithophel to be a failure. Hushai sends word to David to plan accordingly, and David successfully hides. Ahithophel commits suicide. The SAB marks this suicide as injustice, but I don't know what's unjust about suicide, as one does it to oneself. In my opinion, this is more absurd than unjust; I mean, Ahithophel gets rejected a total of one time, and he ends his life over it? What the heck? Who was Amasa'a father? I notice that in this chapter, Amasa's father is said to be Ithra, while in other places, it's Jether, but Ithra and Jether are just alternate spellings of the same Hebrew name. I don't think there's an easy answer, it's just an error in one place or the other.