Two things: Firstly wooden assailants are very dangerous and resistant to gunshot wounds. Your best bet against this sort of wood-be assailant is a flamethrower or an ax.
Secondly, saying that you shouldn't have a gun because you are more likely to commit suicide than be killed by an intruder implies that either people randomly commit suicide for no reason or that people choose to have home invasions. They are not really the same sort of thing so the statistics aren't really a helpful metric.
That said, if you are a person with suicidal tendencies you should keep neither firearms nor flamethrowers (which confusingly are not generally considered firearms) around the house. Axes however are very difficult to commit suicide with, and as such should be kept in the event you run into any would-be wood-be assailants.