The thing is, I don't consider it a sin
That would matter IF you were God... but you are not, so what you consider to be sin and what is not sin is not relevant because the Lord is the One Who says what sin is.
Claiming it is a sickness is what the world does so they can coddle their sin, get attention for their sin, have others celebrate their sin with them, and even make money from their sin.
When ya get lung cancer... you'll be quitting then, one way or the other!