All you can do is hang in there and try to figure out what techniques make things easier for you.

I used to have the exact same problems, but thru years of trial and error have found work-arounds. I now rely HEAVILY on notebooks, Outlook, and my cell phone calendar.

It can be so frustrating knowing that you are as smart and skilled, and able as everyone else, its just that your mind works a little differently. It doesn't make it any easier either knowing that a lot of people don't believe ADHD is a real disorder.