The feeling of "emptiness" or disconnectedness is a complex phenomenon in itself and there are many contributors, but for starters you should explore the strong possibility that the emptiness is really a very forceful suppression of very strong feelings...like pushing something done so far inside you it creates a psychological vacuum...=emptiness...If you can't explore this with a traditional therapist, maybe some form of exploratory meditation will be a way of getting there.
Finally, I find someone who feels the same exact way as me. I feel a little less crazy right now. Like you, the emptiness inside is the most distressing feeling for me (if you can even call it a 'feeling'.. it's more of a void of feelings) I have friends and family around, who care for me, but there is a genuine void inside of me. The more I dwell on it, the more I question who I really am as a person and whether I even have a character inside. But on the other hand, I have moments of happiness and fulfillment.
I just want you to know that you are not alone in this struggle and I will wait for the doctor's response as well. Thanks for asking it!