It happens, I was in the same spot as you when I was 19, so I decided to do add a responsibility of living with an addiction! (don't suggest you take this route). Be happy you DON'T have responsibility, which I am guessing is the case, not that you willingly thru away responsilbility (i.e. ignoring a child, child's mother, etc).
You could be like everyone else I knew at that age, already had one or two kids by that age, living day to day in a job they hate, with a girl that used to be good looking in highshool, but in a year 1/2 she has become disgusting (not ugly, just gross, like don't care about appearance).
My guess is people are pressuring you because you are living a life they can't, one free of their responsibility.
You want responsibility?
Fine, here, I'm going to make you responsible for getting a damn job and saving a million dollars, in one year. Go! That'll keep ya busy
Seriously, "responsibility" will come, and it will suck.