I would take a lesson if I were you. I've taken lessons after a few seasons to just to try and progress to the next level and they always seem to be worth while.
I must also agree with you on the pain of flats. It seems like when I fall on a hard packed green groomer I go "thud" and all the energy goes straight in to the ground. On steeper trails you roll and slide a bit more and I don't think it hurts nearly as bad.
And for completeness sake: don't worry. We've all been there. You'll get the hang of it