Aysha,
I bet you do know why you do this over and over....Only you can come to that conclusion.
That said, is it at all possible that you are so terrified of succeeding, something you may feel is foreign to you for any length of time, that you go on a binge, effectively putting an end to your chances of going forward and then you can explain your failure in pursuing your dreams...because you used again. It's safe...This way you know what the outcome will be........?