am I irritable because I've been in constant physical pain for 12 years or is it because I'm just an asshole?

since it's become worse over the past couple of years, I've noticed that my irritability has increased.

today I read an article on hyper-vigilance, irritability, and pain. being in a wounded state increases fight-or-flight. we've known this, but is that part of it? is it instinct or just a corrupted brain?