Hey there!
I can't say that I personally have similar issues, quite the opposite actually, but my husband definitely has these same issues (we both listen to metal and dress in mostly all black as well, lol).
Because I get to see who he truly is behind closed doors, it has always been very strange watching and interacting with him in social settings. He completely shuts down unless he has some liquid happiness (liquor). He constantly looks over his shoulder, immediately gauges who is talking to, how much respect they deserve, how quickly he can beat their *** if need be... it's very off putting to be honest.
Even after 6 years together, 3 of which being married, he still doesn't fully trust me. Not because of anything that I have done, but because he believes that like everyone else, I will end up hurting him. And he cant allow himself to be that vulnerable.
I certainly have my ideas on why he is this way, and I'm guessing that they are similar as to why you show these traits as well. But I will tell you this... I am also not one to show much weakness, and I personally am very opposite of you and my husband... but I am rarely taken advantage of and almost never hurt by others.
I'm sure this helps you about 0%. Sorry