big rides for a purpose

First of all I am not an athlete, I am active and love a challenge.

   Last spring a friend invited me on a BIG ride, 1200 km bike ride from Vancouver to Banff! ALL in 9 days and all to raise awareness and funds for Cystic Fibrosis.  I have always ridden 

a bike but never done anything like this.  It was daunting, scary and exhausting.  I am over 50 with arthritis in some bits, the other bits just hurt from so many hours a day in a saddle...has anyone else done such a thing and wants to share their experience?