Whats Wrong With Me ? Or Is It All In My Head ?

Whats wrong with me? Or is it all in my head?? Hello I have many symptoms but my mother tells me I am just a hypochondriac, however I feel there is something more going on. My symptoms are lightheadedness, resting heart rate at around 95-110 bpm, low blood pressure, pain in chest, dizziness upon standing up (sometimes will almost faint ie. vision is impaired and etc followed by a tremble and a sharp pain/pressure? in my head), my nose cheeks feet or ears randomly get hot and slightly swollen (maybe that is just bad circulation though), and exercising (mainly cardio) causes a lot of heavy breathing/pain after less than a minute. I should note that I had a normal results on a ekg. What could this be or is just me being a hypochondriac??