I can't even begin to imagine how draining your job is, I work withing a community service organisation and often feel drained by trying to help people in crisis of the mostly non-physical type but it is certainly no where near the pace of an ER.

There is certainly more to life than we know!, I have read about various philosophies and spiritual beliefs since I was young because I was always searching for something to give me hope or answers. That book the Celestine Prophecy was what started it for me in regards to "energy" when I was 14, it is fiction but brings up some ideas for a mind that has never thought of such things truly existing. I have always felt raw and drained in crowds but I think that has a lot to do with growing up in a combative environment and being an introvert like yourself. I have a number of avoidance issues to say the least I find a lot of Metaphysics resources to be of help in regards to empath/energy, it is just often a case of finding the right fit for you