I am sorry your stressing over you trip but I understand how you feel. With a husband with Crohns I know when he is going to be stressed so I feel for you.
The 7/11 technique can help calm anxiety enormously and practising this could certainly help with your journey. You can trick your body into relaxing by using heavy breathing. Breathe in slowly for a count of 7 then breathe out for a count of 11. Repeat the 7-11 breathing until your heart rate slows down, your sweaty palms dry off and things start to feel more normal.
Distraction is also a good idea. I would suggest taking lots of means of keeping your mind occupied on the journey.
Often it is the fear of fear that is the worst and the journey will probably not be as bad as you are currently imagining. Do you practise any form of relaxation? It would be an idea to do some nightly and perhaps you could imagine yourself on the journey and everything going well while you are feeling calm from the relaxation. Rehearsing a positive outcome in your mind can be very helpful.
Good luck. Let us know how you get on.
Kitt, Moderator: Anxiety, Panic & Depression https://www.healingwell.com/donate *~* Not a mental health professional of any kindIt is health that is real wealth and not pieces of gold and silver.~Mahatma Gandhi~