There are lots of reasons why someone might feel anxious. Living in hazardous conditions is one, and sometimes it happens for no discernible reason. But diet is another, because if your body doesn't have all the raw materials it needs to make neurochemicals, your brain can run short of some and then you feel like crap.
This is why, when you feel bad -- and not just with anxiety, anything -- a good first step is to check your diet. Are you eating a balanced diet with plenty of fresh, whole foods? If not, try doing that and see if you feel better. Unlike psychotropic drugs, a healthy diet doesn't have risky side effects, although it does cost more money than a junk diet (but less than drugs).
For anxiety in particular, also check your subjective and objective safety levels. If someone is mistreating you, or your life is otherwise insecure, then diet, drugs, or talk therapy won't make you feel better. You need to solve the problem, then work on restoring your peace of mind.