Is it safe to quit smoking all together at once?

iv heard some say smoke 9 a day then 8 a day and so on but im not im quiting just throwing them down im 17 iv been smokin a month or so maybe iv smoked a carton over a months time im having chest pains witch i believe is from my asthma but im quiting before it turns into something serious because it fells really wierd when i inhale like m throat is closing up i know its not as hard to quit as somone that has smoked 15 or so years but im quiting my throat feels funny right now but i think its just my brain telling me i want one my chestg pain is coming from m back mostly because im 6foot 2 and slep on a barely five foot couch i have a bad back anyway but its enough to scare me and im quiting for good is iut safe to just stop suddenly