Welcome Megan - have you wandered over to the "getting to know you" thread yet? Gives you a chance to meet us and tell us some more about you.
As for your feet, one of the first things I did was replace the insoles with runners insoles and that helped A Lot! Also, flex your feet inside your shoes - often. Don't keep them static. I find when I get off the bike for my breaks it helps me to take my shoes off and walk around stocking footed, just to get the blood flowing again etc. As for fuel, on long rides I try to eat about every hour and to drink a bottle an hour. I may not eat much, rice cake and PB or a gel, or some trail mix but at least something every hour. I find the longer I ride the less "food" I want to chew and swallow so I may switch to the heavier goos/gels towards the end of the ride but every person is different. I also try Really hard to eat a really good meal within 30 mins after I'm off the bike. Hope some of these tips help! and again: welcome!
Life should NOT be a journey to the grave with the intention of arriving safely in an attractive and well preserved body, but rather to skid in sideways, champagne in one hand, strawberries in the other, body thoroughly used up, totally worn out and screaming: "Yeah Baby! What a Ride!"