For The Past 16 Months I Have Suffered With Chest

For the past 16 months I have suffered with chest tightness and discomfort when walking or exercising. Pain is worse after I eat. I have had an endoscopy, colonoscopy, EKG, stress test, and chest x ray. All have been normal. I have been told I have asthma, reactive airway, GERD, and costachondritis. About the time this started, I had an upper respritory infection and a cough that lasted about 3 months. I have been prescribed inhalers, acid reflux medicine, asthma medication, and ibuprofen. All have not relieved the symptoms. It feels like there is something in my chest wall area that is pushing out at times. Area is very tender at times. What is it?