Does your anxiety come and go through out the day?
Or
Are you generally at a low level of anxiety throughout the day?
Valerian tinture works very well with anxiety. You could try "gotu kola" capsules without the other mixture of herbs. It helps clear the mind and relax anxious feelings. You may also want to try taking a sublingual B12, B6 & Folic Acid supplement. It works wonders for mental health and clarity.
Stay away from foods with excessive Sugar and anything containing caffeine such as coffee, cola etc.