Good decision, there's no light in bed :-)
When I was 6 & 7, I'd take a bath and get out and it would be "cold" so I'd huddle, with the towel around my shoulders, next to the toilet! It got so I'd be stuck there, couldn't leave the limited warmth to dry off further, be without the towel so I could get dressed in my PJ's and then get in the warmer bed. My stepmother would realize I must/should have finished my bath by "now" and come in and find me there and grab me up and dry me roughly (and warmly) and hustle me into the PJ's and warm bed, etc. But I still remember how "stuck" I would be (whether waiting/hoping for my stepmother to come and care for me or whether I was just stuck because I'm an always/easily-getting-stuck sort of person) and how "impossible" it would seem to "continue" in the right direction.
Why, since it seems you are stuck in a tunnel, don't you treat that fantasy like a lucid dream and change the images? "See" a pinpoint of light and wonder what it is and go toward it. You could be in a railroad tunnel, under a curved hill in Switzerland :-) (why there was no light at the end for awhile) or, if you want to get "difficult" you could be travelling up Jungfraujoch, all under the mountain AND going uphill :-)
http://www.myswitzerland.com/html/of...ess-92165.html Or, there could be a warm "being" who lets off a light and as you get closer you get more light, etc.