Well you clearly have akrasia. Self-control has variable effects on people. It can be affected because of illness and past experiences and it can be improved through the course of life. You need to change your perception of your 'self' and the adjust the boundaries for that self.
It's all in the mind, so if you can regulate that, you can exercise self control and remove negative akrasia.
Maybe as a start you should focus on increasing your ablilty to defer gratification; that is, to be more able to refuse a small reward now for the sake of a bigger reward later.
As Socrates said, if one judges action A to be the best course of action, why would one do anything other than A? Therefore akrasia could be an illiogical concept, which is where the cycle of self control comes into play. You need to be careful of the inconsistent triad though. Many people of an addictive nature (smoking, gambling etc) fal foul of this.