Antihistamines. Mildly sedating antihistamines (e.g., Diphenhydramine = benadryl) sometimes help with mild anxiety. Herbal tea containing valerian root &/or chamomile can be calming. Unlike most prescription anxiety meds, these are not habit-forming. However, if anxiety is a persistent problem it's better to address the causes instead of just treating the symptoms. Try stress management, relaxation, therapy.
Not meds. If you want to help yourself overcome anxiety, stay away from the pharmacy. Check out books on dealing with anxiety. There are many excellent ones that can teach you ways of dealing with stress and anxious symptoms. Medications can be of help, but the effective ones require a prescription.