This brought back memories. :) The saddle was never a problem to me (girls tend to have a nice fatty layer there I guess), but when I started cycling, and later when my company move 5kms out of the city up on a little hill, the first week was terrible. The second week was ok. Then it was pleasant. The hills have this nice tendency to flatten down when you tackle them everyday. So keep up the exercise, and making it in 20mn when you thought you'd take two hours is interesting...