Hi Garden Gal,
Illogical is a great word for it - I know just what you mean. I have tried to explain it to people (like my mom) by saying it feels like someone has just delivered some terrible news to you, told you something awful and sad - but no one has (necessarliy). All I can say is, try to be gentle with yourself. Do the best you can on your trip. Maybe try to explain a bit about how you are feeling to your friends, as well as how you are getting help. I just came back from a trip too. There were times I had to say "You guys go ahead, I'm just going to rest a little." Also, I asked my T if I could call her half way through just to let her know how I was... Sometimes I just feel better leaving a long rambling message on her machine. Hang in there Gal, keep doing the best you can to care for yourself.