i know how you feel - i had to make a rule for myself - i get one call to the office first theing in the morning - I can check email and bank via blackberry - and I will ask my clerks to do as much as possible via text - only calls i will make are to customers.
i stress to the max before i leave - i look for every possible reason someone would need to call me and try to handle it pre-trip. it can be exhausting.
my last trip - my clerks limited me to one text in the morning - and only responsive texts to cant wait issues (which was only one). they have helped me alot getting over the panic of leaving work by taking up the slack.
but excitement really goes away the weeks leading up to trip and doesnt return really until i get out of my home state of MS - once I cross the state line I start getting excited - and I ALWAYS leave on a Friday so i can 2 or 3 days not even worrying about what is going on at work.