The 2nd Amendment is over 200 years old, and trumps your later day laws.
Let me ask you this what if your brother had say been stabbed to death, would you champion Knife control?, or if he had been beaten to death, would you champion Club control? You are only looking at the method rather than the cause.
Yes people have and will do bad things with guns, but when they can't get a gun they don't turn in to choir boys, they just chose another means.
One example, I'll bring to your attention, Japan has extremely tight gun control, but they have a suicide rate higher than the US of A, so they have no "handgun suicides". So when a gun is used here to kill ones self, it just a means to an end, it does not mean they won't use another method to end their life