Since procrastination is rarely rational (Why would anyone want to experience the anxiety you report?), it's important to uncover the hidden motivations and meanings that allow it to have such an iron grip. For some people, it is a kind of behavioral retention—action being withheld to the point of extreme discomfort. For others, it represents a way to provoke an authority figure (real or imagined) from whom disappointment or punishment is expected if there's a failure to deliver. Procrastination can even be a way of flirting with self-destructiveness: People can receive an addictive thrill from completing tasks just under the wire, as if they've just gotten away with something.
In your case, especially now that you're the boss, preparing presentations at the last minute ensures that you never feel relaxed and may even signal an underlying conflict about being successful or feeling like a real adult. If you feel guilty about success or fearful of the hard-earned freedom that comes from running your own company, then procrastination is a sure way to clip your wings.
The first step to making a change: Ask yourself what you might be getting out of this high-risk behavior. As an experiment, just once muster the will necessary to prepare earlier. As you're working, pay attention to any anxieties that emerge. Does acting like an adult in this way engender feelings of abandonment or isolation? Is preparing something thoroughly scary for you because it might produce a higher level of quality you'd have to match again and again?
Whatever emotions come up will provide clues as to why your instincts all point toward delay. This kind of introspection about hidden motivations is hard to do on your own, but it can unlock more adaptive behavior. If the attempt at self-help fails, and you're a chronic procrastinator in other contexts, too, it might be worth exploring the issue with a therapist. Kerry J. Sulkowicz, M.D., a psychoanalyst and founder of the Boswell Group, advises executives on psychological aspects of business. Send him questions at firstname.lastname@example.org