I've told them that as they feel unhinged, as they cope with emotions perhaps on a scale which they've never before felt, as they adjust to a markedly different culture, as they adapt to so much that's foreign, they'll view their situation objectively if they remind themselves that most, if not all, people would feel fear while confronting such challenges. I've told them to remember that in the choice they made to enter the Peace Corps, they've chosen to conquer their fear.
Most, if not all, PCVs, soon after swearing in as PCVs, freak out to a degree they've never before experienced. If you're a new PCV, you're pushing yourself into new territory, and it's scary because it's unfamiliar. As you freak out, and conquer your fear, remind yourself that many people never do what you're doing. What you're doing is remarkable.
In the context of being deposited into towns where you don't know people, where you're struggling to express yourselves and understand what's happening around you, reconsider what's normal and what's amazing. Every day you're choosing to live ridiculously unfamiliar, insanely uncomfortable lives. When you just walk down the street, in the context of feeling such culture shock, you're doing something which, for many people, is unbelievable, unfathomable, unimaginable, unattainable. Think I'm saying something untrue, falsely flattering, exaggerated? It's accurate, considering that many people let their fear prevent them from ever even trying it, even once in their lives. And you're actually doing it.