chrome1,
I have been there - in very similar circumstances.
I keep my defensive handgun (S&W410 .40) under my side of the bed between the matress and box spring. This makes it tough enough to get to that I must be pretty awake, out of bed, and be able to focus my eyes. At the same time, I can have that weapon in my hand and rack the slide in about 5 seconds.
If I am carrying while out, there is no debate...100% of the time there is round in the chamber, anything less defeats the purpose of carrying it.....however, under the bed at night, I dont do this anymore as it is too easy to reach for the gun in my sleep, and make a really bad choice as a result of being startled.
In the absolute worst case scenerio (I awake to someone in the room that present an actual threat), I need to deal with threat in whatever manner I can, but even if I had the gun under a pillow, I am already at a huge disadvantage. I am a light sleeper like you, if there is a forcible entry, I like to think I would wake up prior to someone entering my bedroom....and all I need from that point is the above mentioned 5 seconds.