Anxiety is 100 perfect a real thing and something many people struggle with through their lives but sadly it's something many people are still too ashamed to talk about.
What does it look like?
It looks like hollow eyes with dark bags makeup can't cover. It's shyly just saying you're tired whenever anyone asks you what's wrong or how you are. It's overthinking to the point of making yourself sick. It's mornings where you can't find the motivation to get out of bed and its nights where you can't fall asleep. It's scary and it's real and it causes you to feel alone because you feel annoying or like a burden whenever you talk about it.
Anxiety is something hard to explain unless you go through it yourself and yet still complicated because for everyone it's different. For many, it's the fear of speaking in front of a group of people so this causes extreme anxiety even when it comes to saying "here" for class. For others, it's small frequent panic attacks for things like being late so it causes them to show up rather early for everything. For others, it's the fear of people leaving or becoming a burden to people so it causes them to be quiet or have a hard time letting people in. And there are dozens of other ways anxiety effects people!
I wish I had the advice needed but sadly I don't. I have been there though and I've seen it affect my own life and I know it's hard. I think all we can do is be understanding and less quick to judge, but rather we need to be there for people who struggle with anxiety and listen to what they're going through rather than telling them to "get over it" or diminishing what they're feeling.