Lottie,
I never travel out the country ,recently I had to travel 3 hours trip to a visit a sick relative , I can't sit for so long or walk,either way is hard for me,I was sure to take my anxiety meds 30 minutes before leaving home, second my first dosage of pain killers, if you travel obviously over the seas, your sleeping pill will come handy also 30 minutes before getting your flight,about the switching cars ,taxis, you are in good hands,trust your husband and daughter,they know for sure what to do, relax and enjoy your trip,is normal to feel scare but enjoy your life,don't postponed happiness for being scare , kick scare butt far away from you , and enjoy your beautiful family time , you will for sure have the best time ever, check your list of meds with original bottles obviously ,specially pain killers ,anxiety or sleeping meds, have enough meds for the trip, a book to read , and enjoy don't worry.
hope you a nice trip and relax,blest wishes from Jesika .
Ps forgot to mention, for sure you will be in the plane maybe for more than 5 hours,make sure you take with you one of those little pillows like a horseshoe shape or U form to relax and hold your neck,they are available on bath,body and beyond ,the ones like as seen on TV, round and can be shaped as a U, hope you get the idea ,they are not heavy but comfi.