My own worst enemy sometimes....

Today in my nutrition class we discussed emotional eating.  And then I immediately went to Albertsons and bought mac and cheese, 4 cheese pasta and m&m's.  I also bought tomatos, bananas, carrots.  So far I've eaten one banana, a handful of m&m's and all of the mac and cheese...all because I am home alone and can get away with it.  I am not angry, not upset, not lonely, not bored, not stressed.  So then, why do I undermine my own self?  I am working my butt off at the gym and eating really good during the week...but come Friday I blow it.  I am doomed.