You need better data. Guns are used in self-defense far more often that David Hemenway asserted.
Hemenway only counted incidents in which the gun was fired: the vast majority of defensive gun uses don't involve any shots fired.
In a 2013 study, the CDC concluded that people who used guns in self-defense generally had better outcomes than those who tried another method.
Gun use in suicide has been declining even as gun sales have surged. Hanging and other types of asphyxiation are on the rise.