You overstrained yourself. I don't recommend using the healing hands on more than a few people at a time, and it's best to concentrate on one person at a time. This is a potent spiritual modality and you can strain yourself by trying to do too much with it too fast!

As far as I know, the Essene healing system is not subject to the same issues as ritual magic, and many branches of Essene spirituality today are strictly vegetarian. (You might find the books of Edmond Bordeaux Szekely worth reading, for example -- he was an Essene and very deeply into the vegetarian diet.) So you should be fine. Well, provided you don't keep trying to lift shipping containers with your bare hands. ;-)