I know how you are feeling. I left my pup with a very good friend who has two Yorkies. They are actually best friends with my dog. I would call at least once a day to check on her. She did very well and had the best possible care. It's great to know they are well taken care of, but that doesn't help with the guilt you feel for leaving them behind. Don't be surprised if your pup tries to ignore you when you get home. That happened to me a couple of times when I returned home. It won't last long. Maybe mine was trying to teach me a lesson. I felt horrible.
Have a great trip!