I Go Through Periods Throughout The Day Finding Myself Having

I go through periods throughout the day finding myself having periods where I gasp for breath, I have been told that I have nodules growing on my lungs. I am not a smoker nor have I allowed smoking in my home, but grew up with two parents that smoked. I do have severe anxiety, but this did not start happening until I had three major back surgeries within 6 days of one another, what should I go to my doctor and begin with?