this may be The Dumb Question for the Day, folks...

With T, working through Pete Walker's book "The Tao of Fully Feeling". As a way of bringing up repressed emotions, Walker suggests a mind-body exercise which begins with lying down comfortably and concentrating on your breathing for about five minutes... in ... out ...

Sounds simple & very relaxing but the problem is, I don't ever get past this point. After a while it becomes very laborious to breathe at all and eventually I feel the breath go out, and I find myself thinking how nice it would be to just not have to inhale again. No bad memories from the past (or present), no emotions really, just I don't know, weary.
And when I find these thoughts (of not breathing) I go and I get up; that's the end.

Is this something to be concerned about (3 out of 3 times so far)? How on earth can a person fail at mind-body exercise?!