Probably around three months, but your experience may vary.
But: If you are in trance, in a deep enough trance to project, you should have no body awareness whatsoever. The symptoms you get come from your mental processes, and focusing on your body sensations actually keeps you from having the body dissociation you need to get out of your body.
It's ok to focus on your body when you are doing energy work, but when you are past that initial step on your routine, and are now trying to get in a trance, forget about your body, physical or energetic (at this point they're indistinguishable), and visualize what you want to visualize or do whatever trance induction methods you are doing. Focus on what you see or hear, (in your imagination) do not think of body sensations at all. When the symptoms get dramatic (such as vibrations, movement or sounds or some combination) then you start your exit technique (rope or whichever you picked) and do that until you either exit or pass out from exhaustion. Just don't go to sleep no matter what happens.