Are your symptoms interfering with your ability to function in life right now? A messy room as a child is not a red flag for ADD. It actually sounds like something any child would do- disobey because they would rather play with a doll as opposed to cleaning their room. Some doctors are quick (possibly too quick) to diagnose ADD and prescribe medication. I suggest you find a qualified specialist- a psychiatrist or a neuropsychologist- who is able to do a full evaluation for ADD. A thorough evaluation will take a few hours and may even include computerized tests and other puzzles and stuff to test memory, impulsivity, etc.

As for treatment, I've found ADD medication to be quite expensive if its name brand. Most medications come as generic forms now and are a great deal cheaper but I've found them to be less effective. It depends on the individual though- you may not even notice a difference.

Anyway, I would begin with getting a good referral- possibly from your GP.