You need to get a good physical examination.  It might be something as simple as an under-active thyroid gland that makes you feel listless, or drugged, as you had said.  If you are not drinking at least eight glasses or water everyday, dehydration can make you feel light headed and dizzy, or as if you are about to pass out.  The anxiety you are experiencing, is making you feel even worse.  There is always a great fear of the things that we do not understand.  So, with that thought in mind, why not get a medical opinion and some information, and you can take your life back.  A simple blood test or two, would answer a lot of questions.  Those answers would erase your fears.  It is easy to sit and blame the computer, or a lack of sleep.  I challenge you to get the answers you need; and then start sleeping, functioning and enjoying your life once again.