I Am Having Breathing Problems

Im 26 YR old female that recently stoped smoking but did so for 11 years before I stopped. The last 3 mths I've been having trouble breathing and my lungs hurt so bad. Pain and burning and it seems hard to take in a satisfying breath. Its suddenly hard to do small things like walk across a room talking at the same time. I had asthma as a child but have never had trouble with it as anadult I fear the worse and don't have insurance. I went to the er a mounth ago and they did a xray and said my lungs looked fine but that they wouldn't long because I smoked so young. He never told me strait out or did any breathing test but on my discharge paper they put cops. If this is the case why didn't he tell me. Why is it all of a sudden so bad. And is it normal for it to pop up so bad out of no where. Could this be a lung infection or a related problem with my heart. Because I get sharp pains in it sometimes. ( daily) oh also dr said oxygen levels were good and so was blood counts.