is that going to affect my health/life expectancy to badly? many relatives on my mothers side have smoked long term, and they’re health seems alright and my grandparents have lived for quite along time despite it.

i don’t really care if it shed maybe 2 years off my life, i just want to know how badly it will affect me.

thanks in advance!
btw i dont want kids! and i don’t smoke around other people most of the time.
i’m 18, and i don’t plan on doing this for ever. i’ve been smoking for a year and i know i’m not addicted because i can go a week without it, i just don’t choose too.