I'm Seeing A Cardiologist Next Week But I'm So Frustrated

I'm seeing a cardiologist next week but I'm so frustrated that so far my regular doctors and even a visit to the ER could not help me find anything. I've had high blood pressure for the first time in my entire life, it went as high at 185/106 but it currently at 124/76 (I'm on bp meds) which is a relief but the problem is the chest discomfort, lightheadedness, exhaustion that continues. If I go upstairs I get winded, if I bend over it hurts.
The thing is I've had a chest xray, blood tests, EKG, CAT scan and a stress test....all FINE. But they still want me to see a cardiac doctor which I am happy to do as this is rather upsetting. Do you have any idea what this could be?