I would go back to your doctor and make sure there isn't something they're missing - no one can diagnose you here but whether its something physical or mental its better to get a handle on it now before you feel even more bogged down by your symptoms. You could well be experiencing side effects from the sleeping pills so an adjustment might be needed. If you're feeling 'empty' i can definately relate to this - it doesn't really matter how much i fill up my day with i still feel something is missing. So i have no advice on that front but if its any consolation a lot of people here, myself included, feel like that too. I hope your situation improves.