I'm 22 years old and I'm currently a first year medical student and I'm learning about all the diseases, not to mention being stressed out and I think I'm either becoming a hypochondriac or anxiety ridden or I am developing a heart condition due to stress.

Sometimes I get "stabbing" sensations in my heart and lately I've been feeling light headed and dizzy and sometimes my heart feels like it's arrhythmic and a lot of the time I can feel blood pulsing through my heart.

I used to get full blown anxiety attacks in college during finals when I had caffiene and ever since then, my anxiety has been manifesting itself in different forms or I have a chronic illness that is uncovering itself when I'm stressed. I didn't think anything was wrong until I have had these stabbing pains.
And right now we are learning about cardiac pathology and the hypertophy of cardiac muscle fibers and it's freaking me out. I moved to the midwest and I haven't been sleeping regularly and I'm constantly studying and I'm learning about all these health problems. I just want to go get a stress test done to know once and for all if all my symptoms are really just in my head. I know that anxiety can cause manifestations of pain but I would like to know if I am ok.

What should I do?