What Causes Muscle Spasms In Chest And Neck?

I went to the doctor with chronic squeezing sensation on the right side of my chest and neck, with spasms (retractions?) in my upper chest and neck on occasion, sometimes worse with exertion on a hill or stairs (I can do my jazzercise with no problem unless I have to jump a lot). Sometimes the pressure and squeezing makes me feel short of breath. I gasp myself away at night when I am sick with a cold or sinus infection and I constantly feel fuzzy as if there is cotton stuffed in my head. This has been on and off for about 20 years but no one has addressed it until now. A recent chest xray showed mild pulmonary hyperinflation. I am 47, a non smoker, but was a nail technician and around chemicals for about 10 years in my early 20 s. I do not have a cough but sometimes I get post nasal drip mucus that I can feel in my throat.