This one is not something you can just pick up for your trip but is useful both when traveling and in all other parts of your life. There's
evidence that practicing mindfulness can help with anxiety and depression, even though it's often sold as a miracle cure for a myriad of other things.
Try some
mindfulness exercises. You can find more in-depth information from many sources, for example, this
book. There are also many apps available that walk you through mindfulness exercises.
Keep in mind that mindfulness is not something you will see immediate results from. It takes considerable time and practice for the effects to show, but there's no better time to start than now.