What you're going through right now is caffeine withdrawal. That means you're getting the worst symptoms NOW. There is life after caffeine. Trust me, I have two bachelors degrees. You really need to focus on getting enough sleep. It IS possible. Have you considered doing your Grad studies part time? That would take a bit of the pressure off, and allow you to get enough sleep to stay alert. Besides, once you're through the withdrawal of caffeine, you won't feel so tired and sluggish. I truly hope that you will get through this without it destroying your academic goals.
-------------------- Formerly HanSolo. IBS, OCD, Bipolar, PTSD times 3.