Have you considered it may be a health issue that makes you feel "braindead"? I usually feel the need to take a nap (after 8+ hours of sleep), aside from feeling tired in general and am awaiting blood work results. What about setting up a temporary basketball hoop where you live. Sorry if this isn't helping, trying to think of some suggestions.
That's quite the amount, lol. What is it that keeps you avoiding studying? I think that you should use things that you like to do as motivation factors. Treat yourself to say, a video game after you study a said amount of hours in a day. There will be days where you fail, but more or less it should get you into the habit of picking up a study routine and biting the bullet. Don't want to start freaking out near the test dates because you have to start studying at the last minute.