I've done this too. However, you have to be prepared to walk or be prepared to buckle down and do the work. At the end of the day, they are paying you to do what they want you to do.
> I said "I would like to kill [someone who is my friend at Amazon]."
Sure, maybe you said it in a moment of passion, but there is no way in hell they can just let that slide.
> During that time I told anyone who would listen at Amazon what happened.
Also, no chance in hell that a company is going to continue letting you do this, and in many cases you would be fired on the spot.
This is 100% on you, and sure, due to stress, but your story showed that Amazon was actually a lot more forgiving than many companies would be.