I dont know about foods that will help with anxiety. I know there's foods to stay away from. Caffeine and alcohol are things you want to stay away from. And really a lot of the new focus of mental health treatments are looking at mindfullness and eastern philosophies. So yoga, meditation, relaxation exercises, breathing exercises are all the latest things are being studied and have been found to be helpful (empirically, i'm sorry but i'm a huge stickler for needing research to backup stuff)
I used to have a real issue with stress- something that really helped me out was a supplement from "Nature's Sunshine" called "Nutri-Calm" They also have a couple of others that you may be interested in, depending on how and where the anxiety is effecting you. You should check out their website- it is wonderful!!!
Also, this isn't natural foods, but vitamin B (all of them) and magnesium help a LOT for anxiety. I used to struggle with panic attacks and together with my meds I started taking a supplement for both. It takes the edge of the anxiety and helps you sleep better.
yes, you can try a nice cup of chamomile tea or try doing some yoga or meditation or going for a relaxing massage.