Anxiety symptoms and possible hypoglycemia ?

Hi, welcome to the ehealth forum and I am glad to help you.
You seem concerned about the symptoms of anxiety, depression and agoraphobia in your partner. You fear that the symptoms might be due to hypoglycemia and not anxiety as she has not benefitted much from the treatment for anxiety.
A low sugar level in the blood found at the time a person is experiencing typical symptoms of hypoglycemia confirms the diagnosis in a person without diabetes, especially if the relationship between a low sugar level in the blood and symptoms is demonstrated more than once. If symptoms are relieved as the sugar levels in the blood rise within a few minutes of ingesting sugar, the diagnosis is supported.
In those who do not have diabetes, diagnosis requires demonstration of low blood glucose levels accompanied by the usual symptoms. Depending on the type of hypoglycemia, blood glucose is measured either during a glucose tolerance test or after an overnight fast. Further tests and a detailed patient history are then necessary to determine the underlying cause of hypoglycemia.
Since symptoms of hypoglycemia are vague and often non-specific, many other conditions can mimic hypoglycemia. In order to establish hypoglycemia as the cause of the patient's symptoms, three criteria must be met. The patient must have symptoms of hypoglycemia with a documented blood glucose level of less than 45 mg/dl. Additionally, the symptoms have to resolve completely with the administration of glucose. These diagnostic criteria are referred to as "Whipple's triad."
So, to establish or rule out the diagnostic possibility of hypoglycemia in your partner it is essential to carry out a blood test to satisfy the Whipple's triad which is the one most commonly used for the diagnosis of hypoglycemia nowadays. Further, your partner had decrease in symptoms with medications for anxiety but the problem is that she is not compliant with medications at present. Your partner shall continue consultation with psychiatrist and consider counselling, cognitive behavioural therapy, group therapy and psychotherapy along with medications to make the results more effective.
Hope this helps. Take care.
Note: This post is not to emphasise final diagnosis as the same cannot be made online and is aimed just to provide medical information and no treatment suggested above be taken without face to face consultation with health care professional.