Maria, I can sure relate to missing him and worrying about him while you're out of town. I'm convinced I'll never have another truly great vacation until I'm about 80 and don't have a cat anymore. Somehow we've got to get over this! Here are some thoughts for your consideration:
--Think of it this way: The fact that you're still able to take and enjoy a vacation is one of the reasons you're willing
to have a pet. By still enjoying vacations, you're just exercising your right to do something you reserved the right to do. If it weren't for that, Tiger might not have a home at all.
--They're cats. He may get bored (in which case he'll probably just fall asleep), but they don't "miss" us like we do them. He probably just detects that something's new with the household routine, but I've got to believe that because he was left in the house, he knows you'll be coming back. It's not like he's being boarded where he could very well think he's lost his home.
--I've been told, and I'd like to research this a little more, that cats have a very poor sense of time. You being away for 5 days probably feels roughly the same as you being away for a weekday, I've been told.
--By arranging for the cat sitter, you're giving Tiger a chance to get to know someone else. That's probably good for him, in terms of having a new person to smell, get familiar with, and play with a little differently.
--Again, would you have gotten a cat if someone had said you could never take a vacation again? No. So you're just doing what you planned to do, and Tiger should be thanking you for getting some rest, relaxation, and change of scenery so you can come back and continue to be a great cat-mommy.
--Keep in mind that even when you're home, they often go off by themselves for hours at a time. Even the most affectionate of cats, like Murphy, seeks out his alone time. It's very possible that if you were home at this moment, Tiger wouldn't even want anything to do with you.