I have had anxiety my whole life and I currently take zoloft for it. I have received tons of psychology, psychotherapy and even experiential training as well as church. Certain forms of therapy will help to a point however if it is chemical as well then only treating it chemically will help.
It is something you will need to discover. I will say this, the rights meds can change your life, the wrong meds are truly hell on earth. Always trust yourself as you make decisions about your mental and physical health.
Getting tests done to see if your body is lacking anything I think could be a great eye opener. So it is either chemical, psychological or both and I think Eowyn pretty much nailed it.
Exercise and eating well and enough sleep of course always helps.