Personal trainer Matt Hart replies: If you are addicted I can think of worse things to be hooked on. When you exercise you produce natural endorphins (similar in chemical structure to morphine) and these relax you and deliver that 'exercise high'. There is a chance you're addicted to this feeling, but I can't see it giving any long-term problems as long as you get your exercise. If you miss exercise and become irritable to the point of being a nuisance, there's reason for concern, but nothing that isn't curable with a bit of gentle exercise.
But exercising as regularly as you are though, it's important that your exercise programme is structured properly. If you exercise hard every day, week in week out, it's not healthy. Devise a plan that mixes up the intensities of cardiovascular work, and with the weights, split the body up into different parts so that you're targeting different muscle groups on different days. If you have problems doing this yourself, you should book an appointment with a trainer or instructor.