Upperback pain and breathing

For the last month and a half I've been having pain in my upper back that runs between my shoulders anytime I do anything that raises my heart rate. Occasionally it will come on when I am sedentary, but it is primarily when I am attempting to be active. I've also been having breathing difficulties for about a year now that my doctors have written off as "anxiety". I've heard of this type of thing before being a clot or blockage that is causing the pain, so I haven't been working out, which is upsetting since I am typically very active. I am 21 and female; I am not on any hormonal birth control and I don't smoke; however, I have high cholestorol (that I've been attempting to lower) and my father was suffering from heart attacks in his early teens. I am worried that this could be a blockage, but I don't see my doctor again until October 16, and I don't want to run to an emergency room if there isn't much chance of it being anything serious.

Anyone hear of anything similar to this?

[Spektrocia]

I should add that last november when I started having chest pain and difficulty breathing, I was diagnosed with a possible PSVT, so I had a bunch of tests including: my thyroid, pulmonary blockage, electrocardiogram, Cardiolyte stress test, numerous ECGs, tons of chest x-rays...maybe a few more that I can't think of, and my cardiologist says that they came back fine. which is where the anxiety diagnosis came from. I don't think that this is anxiety. I have had anxiety attacks in the past, but I can tell what they are and understand that I have to let them pass through. These symptoms are different, and they persist regardless of how I am feeling.

[dtara]

did you ever find anything out?  It sounds so much like my symptoms.