I suffer from a.D.D. Will I be able to get a medical marihuana card for a.D.D.?

Probably not. Add is not one of the disorders included for "medical marijuana" cards here in arizona. Pharmacologically also, I don't see the logic in prescribing marijuana for add.
Not Likely. I do not live in a state in which medical marijuana is an option, but I would not see any reason why you would be able to justify medical marijuana for attention deficit problems.