A right delayed is a right denied?

You can't sue anyone.  You should have applied sooner.  They can take as long as they need to to approve you.

your state legislature or congress.  not that you'd win, of course

You get to sue the person who attacked you.  Period.   Whilst it is your right to bear arms under the constitution, your personal safety is never the responsibility of the government. 

In short, you don't get it both ways.  (p.s.  if you think a firearm is the only means by which to defend yourself - you have a whole slew of other issues that need to be address).

There are no background checks on colonial style muzzle loaders. Use one of those in the interim. You can disable the intruder then use your gentleman's sword to run him through if necessary. 

Try getting some psychological help with your unfounded debilitating fear.