Hi, Nannen! I do travel frequently and from what I was reading in your post my best advice to you would be to relax! You didn't have a positive statement in the whole post so you are dwelling on all the negative things you THINK will happen. None of us know the future so you don't know for sure all of these things will happen. But, you are worrying about them ahead of time which is causing stress in your body which is causing more pain. This type of thinking seems to become a self-fullfilling prophecy.
Think about all the good reasons you are going on the trip. Think about all the new sights you'll see on your car trips. Be sure to stop every couple of hours, though, and walk around so you don't get so stiff. Also, print out a copy of the gentle stretching exercises that are in the Fibro 101 thread...second thread on the forum...and take them with you. These can be done in the car and on the airplane and that will help you stay more flexible and in less discomfort.
Lastly, take a good book or some hand held games that passes the time. I have a Nintendo DS Lite that I love. I bought Clubhouse Games for it. There are over 40 games to play and I use this on flights. Before you know it, you are there!
So, think positively. There must be a good reason to go on this trip so focus on that abd have a great time!
Sherrine