CBT is found be helpful but it takes 8-12 sessions and commitment on your part to do inter session homework.However in severe anxiety medicines are first choice You will start seeing positive changes by the 4-6 sessions. Although diet is not the first recommendation in severe anxiety fruits like banana and foods rich in omega fatty acids like fish are of some benefit but these are add ons or adjuvants to medicines

Hi We need to know more knowledge when you say severe anxiety.... Is it severe according to you or as diagnosed by a doctor? What do mean by antidepressant doesn't suit ur body.   ..have you used previously n had side effects.Suit is very vague term to understand...we beed lot of details For how long did you use? Have you discussed about side effects of drugs with your doctor? Did change of drugs was an option given to you? If you haven't tried medications n worried about starting?? Psychoanalytic psychotherapy can be helpful to understand underlying reasons for your anxieties. Therapy can be helpful prevent relapses. It's a slow process....lot of studies say minimum of 3 months (weekly once) or 20 sessions  to see  effectiveness of therapy

CBT is quite effective for Anxiety and Depression. You may need a total of 8-12 sessions but you may start to feel better earlier depending on your symptom severity. There is no diet restrictions for Anxiety or Depression. Can eat yellow fruits for temporary elevation in Mood.