Question

I often wake up 60 to 30 min before my alarm, because I have to pee. 
Instead of getting up, peeing, and then going back to bed for the last 
few minutes of time available to me for sleep, I lay in bed, trying to
ignore the fact that my bladder is about to burst and progressively
getting more and more painful. I manage simply to roll around in bed
finding the most comfortable position that does not press more on
my throbbing bladder, squeezing my eyes shut and hoping that I'll
some how manage to doze off. Then, my alarm goes off and I have
succeeded only in using up my last hour of sleep so that I could jump
out of bed, tired and annoyed with myself, try to throw on some
clothes without losing bladder control,and rush to the bathroom
before I pee my pants.
Why do I do that?