This can also enable some Empaths to start having claustrophobic tendencies which you can learn to battle and control by observing your thought patterns. Much easier said than done though… The draining is because you are just absorbed with all this excess energy from feeling everyone else and their emotional bodies. I would work on shielding and Centering <3
Overactive empathy: http://theawakenedstate.tumblr.com/tagged/empathy
Hope this helps
Namaste