First thing to remember is that ALL weapons are "Force Multipliers." A firearm requires less training and practice time to reach a minimum skill level than any other weapon. A firearm requires less physicality (strength and athleticism) than any other weapon. A firearm more effectively acts as a Force Multiplier than most other weapons with similar size and weight constraints.
A firearm can be quite effectively used at close range. There are many cases where a firearm has been effectively deployed at "Contact Range."
True for any weapon.
The firearm is the PREIMENENT weapon of our time. Literally, nothing else performs the role as well. That said, it is not for everyone. While a firearm requires less training for effective use than other weapons, it does still require training from a qualified instructor and that may not be available to you. It also must be legal to carry and use, and that, as we all well know, is varied depending upon location and even the age of the user. And, unfortunately, there is an illogical and undeserved stigma attached to firearms which may deter its use for any number of reasons.
This is a myth. Firearms are fine as close in weapons and there's no reason in the world disqualifying one as "too fast for a gun to be used" which would not equally disqualify any other weapon.
If you cannot, or will not, use a firearm for whatever reason, I prefer a cane in defense. An expanding baton may be equally disqualified for you but is an OK option if a cane is not. Another knife can sometimes be effective. All of these option require vastly more training and physicality than the firearm, but there you have it.
A good set of cut/stab-proof undergarment are also quite effective.
Peace favor your sword,
Kirk