I have a problem with binging and purging...?

...but it isn't constant like bulimia. For example, the other day I opened a bag of chips, sat down and watched TV, and the next thing I knew, the bag was empty. So, since I felt really bad about eating the whole bag, I chugged a bunch of water and made myself purge it. I know it's an awful habit, and if I don't stop something terrible is going to develop from it. I know all the risks of it, like esophageal damage and all that stuff, I would just like help (the thought of seeing a therapist scares me). How can I make myself stop?