hmm you gotta get a grip on your fear...I am not knocking you..as everybody has some now and then..you gotta learn to use it better though..the right dose can be healthy and give you the edge..But I think perhaps you are waiting and expecting and attack to occur? You mentioned you cant see at night? Is it the fear of suprise in the dark? Also your size is irrelevant..i know plenty of short fat people who can really dish it out. I would advise you to start lifting some weights..get physically fit..the excercise will improve your confidence for starters.
I guess I just dont see how carrying a firearm wouldve improved your situation as you described...maybe might have even worsened it?