Can your body self-sabotage?

Like most women that want/need to go on a diet and exercise, I could easily br crowned Queen of excuses and procrastination. However this time I was determined, or so I thought, but then hayfever, sinus and a cold all hit at once like storm Gareth outside. Proper nose blocked, no sleep, constant sneezing and that not-so-lovely pressure in the forehead. Now I wonder, is it possible that it's all underlyingly psychological? That my body is self sabotaging?