How difficult is it to quit smoking after a month?

I sort of unconsciously picked up smoking during a stressful point in my life, and I realize now that it’s stupid and I’ve gotten rid of my cigarettes and I’m starting tomorrow to quit. During this past month I’ve smoked somewhere between 5 and 7 cigarettes a day. I have never felt addicted, necessarily, but I know I could be once I stop. I’m just wondering how hard it’s going to be, and how long the crappy feelings are going to last. Basically, I need some motivation and reassurance.