Quitting smoking - Day 1

Ok so some of my new goals consist of doing things one step at a time. Today is the first day I didn't smoke at all. All day long. I usually smoke about half a pack a day. I'm really on edge with this. But I have to quit. How can I be a dental hygienist who smokes. I really stink. I can't breath lately, I have all this phlegm that I'm constantly coughing up, which is just the grossest thing ever. Ok so...Today is DAY # 1. Well it's only 9:06pm so Im really hoping that I can stay strong.