My son is 8 years old and has ADHD. I spend much of my time being and feeling so frustrated and angry. Forgetting and not finishing tasks is something I know very, very well! Michele, please don't feel guilty for feeling this way. I am pleased that you are taking your son to a doctor, and as justsignmeupalready said, if the doctor is good, your son's self esteem will not be hurt any further. You have done a good and courageous thing in getting help for your son. When my son first went onto medication he said that at least he could hear his thoughts again and not a gazillion (his own words) other things.
Please let us know how everything is.