Asthma?

I have been exercising consistently for 6 months. My body feels great but I have had a hard time breathing well and that has been the hardest thing for me. I stopped my 5k training because I was struggling for breath so badly.
So today I was swimming and sort of gasping for breath and wheezing a little and I sort of had this duh moment when I thought "maybe somethings actually wrong with me."
I just assumed that my breathing trouble was a result of being obese (maybe it is) but I looked up the symptoms of exercise-induced asthma and they all fit. So I set up an appointment with my doctor.
I don't want to have asthma, but if I do it would be nice to know and to be able to breath easier while exercising. I would love to train for a 5k. My body feels like it could handle it, my lungs have disagreed.
I will find out next Friday.
Does anyone have exercise-induced asthma? Has it affected your work outs? Did you notice a difference after you were diagnosed?