Our minds do what we tell them to do and make us what we tell them to make us. We are what we tell our minds we are. So quit using identifying phrases like "I am" when referring to negative behaviors. All you are doing is reinforcing the self-imposed image that this is who you are, rather than what you have done. Instead, try using past tense phrasing like "I have been" or "I used to." i.e. "Yeah, I have been guilty of procrastinating" instead of "Yeah, I'm a procrastinator." An even better phrase might be "Yeah, I used to procrastinate, but now I don't."