Congrats on the long ride!
For the saddle- it may be that you just need to adjust to riding more. You may need a new saddle. There are tons of threads about people's saddle woes. My personal experience is I just had to get my sit bones acclimated. I used to whine about my saddle all the time, then I started to complain less as the miles added up.
Fig newtons are a cheap way to get more energy. I like to carry Sport Beans and Luna bars on the longer rides. I usually have one 24 oz Polar bottle with water and one 20 oz Polar bottle with NUUN (sugar free electrolyte replacement). Sometimes on my weeknight rides I carry a few newtons in a baggy.
Amanda
2011 Specialized Epic Comp 29er | Specialized Phenom | "Marie Laveau"
2007 Cannondale Synapse Carbon Road | Selle Italia Lady Gel Flow | "Miranda"
You don't have to be great to get started, but you do have to get started to be great. -Lee J. Colan