I'm wondering how you know it's only one lung? It would seem to me that a person would not be able to tell that unless they only had one lung.
Regardless, once you have asthma, you have it for life, although it may be "quiet" for a period of time as it may have been for you. However, your symptoms during and after hockey do sound like exercise-induced asthma, which many people have. (If you look in Dr. Enright's FAQs at the top of this board there is a good FAQ on exercise induced asthma, which you should read.) And it's extremely common, if not guaranteed, that a person with asthma who gets a cold or the flu will experience a worsening of asthma during and after they get over the cold.
At this point it would be an excellent idea for you to visit your physician to discuss this and get appropriate medications. An albuterol inhaler may be simply all you need to clear up symptoms of the exercise-induced asthma. But you will need stronger medications to clear up your asthma symptoms after a cold, and your doctor will know which ones are right for you.
Asthma IS frustrating, no doubt about that! We all feel that way from time to time. Ultimately though we have to accept that this is how it is for us and deal with it constructively rather than ignore it and hope it will go away on its own. At this point you need to take good care of your lungs, because they have to last you a lifetime. If you don't take care of them now you will have more and more symptoms more frequently and have worse lung function as you get older. So don't wait to schedule your doctor's appointment.
Just think, by controlling your asthma with your doctor's help it may become a rare instance where you have symptoms during hockey, and your symptoms after a cold would be minimal. . . . that would be great, wouldn't it? It IS possible, but only with appropriate medical advice and treatment.
Hope these thoughts help you figure out what you want to do. Take care & good luck. Judy
P.S. I have read some research that suggests that kids who grow up in a house with smokers tend to develop asthma more commonly than kids who grow up in a smoke-free house.