Why would you snort vicodin? Is it so it hits you faster or something well i agree with the other guy you probably got a perforated septum if you been doing for a while.
Not a doctor here, but just a thought... Could the pain killer be relieving the pain from the nostril? Why not swallow the pill instead.
I can tell you that you're probably burning a hole in your septum. And, I have one from nasal steroid use. It's not fun.
See a doctor. There has to be some treatment such that you can break this pattern.