Anxiety takes on different lights and different symptoms for each person. Each person has anxieties about different things that are related to their own life. People who aren't living with these types of disorders are not able to fully understand how it is to live with the thoughts and emotions that go hand-in-hand with everyday life.
Some individuals try to fix people with anxiety. By saying statements like "don't stress", "make the best out of it", "there's nothing to worry about", "that's silly to worry about that." But when someone who is living with anxiety hears these statements, all it does is create more shame and more worry about worrying. Now they are only worried about the event or situation they were previously thinking and speaking about, these comments lead them to then worry about worrying.
Instead of making the above statements to individuals with anxiety. Choose to say "how can I help?", "let's talk through what you are thinking about", "I'm here to support you", "that sounds stressful, let's talk this through." Instead of shutting the person down, and trying to avoid talking about their anxieties. Choose to use positive statements. Choose to be supportive and ask how you can help them through the state they are in.
Individuals who are living with anxiety are able to understand what has and hasn't helped them in the past. Anxiety isn't easy, it's not just a quick fix. Sometimes individuals with anxiety disorders just need to talk about their thoughts out loud and they don't need a response from anyone.
Be as supportive and use good listening skills to help the individual through their anxiety. Don't try to fix them, because that only makes the situation worse. There is no need to fix them, all you need to do is support them. Be a friend don't be a fixer.