What Causes Shortness Of Breath, Chest Tightness And Soreness In Shoulder Blades?

Question : I am a 36 year old male. I have had what feels like shortness of breath on and off (mostly on) for the last 4 months or so. I was also experiencing a feeling of tightness in my chest, so had all heart tests done (EKG, Stress, ECG.)

More recently, I have started having a tender feeling/soreness in the area where my shoulder meets my breast plate. On the right side. Doctor said possible costochondritis, but I'm not totally convinced.

In addition, I have had an almost constant feeling of almost a lump in my throat, and some hoarseness.

Because I am something of a hypochondriac, my doctors have all said that it is being brought on by anxiety. I am of course worried that it is something worse, like a cancer. Or, less gravely, esophogeal reflux (tried protonix, didnt seem to do anything)

I have had a CBC(12/30/15), and a comprehensive metabolic panel in which everything was normal except slightly elevated Glucose(102). Blood Pressure and 02 Sats are always perfect.

With all the testing I have already had done, is it likely that this is something serious? I have made an appointment with an ENT, are there any other doctors I should be seeing?