When you first get your braces on, your teeth will hurt for a few days, as they will every time you get your braces tightened or your wires changed.
Chamomile is also popular for anxiety in children. Fennel. Fennel isn't for anxiety specifically, but it is linked to treating some of the most common symptoms of anxiety, including digestion, coughing (many with anxiety have a nervous cough), and asthma (anxiety can exacerbate asthma symptoms).
Some herbal supplements reduce anxiety without making you sleepy (such as L-theanine), while others are sedatives. Valerian (Valeriana officinalis) is squarely in the second category. It is a sleep aid, for insomnia. It contains sedative compounds; the German government has approved it as a treatment for sleep problems. Valerian smells kind of nasty, so most people take it as a capsule or tincture, rather than a tea.