Benedryl or namely Diphenhydramine(the chemical name) can give you a feeling of euphoria. It is not safe to take in large amounts and should not be used in this manner. but if you are going to BE VERY CAREFUL! 25-50 mgs is the normal dose. if you take more than that you could go into respiratory or cardiac arrest.
Insulin deficiency (symptom description): For a medical symptom description of 'Insulin deficiency', the following symptom information may be relevant to the symptoms: Diabetes-like symptoms (type of symptom). However, note that other causes of the symptom 'Insulin deficiency' may be possible.
Insulin reaction (hypoglycemia) An insulin reaction is the result of low blood sugar and causes anxiety, hunger, shaking, dizziness, and more. Hyperthyroidism Hyperparathyroidism can cause fatigue and weakness, increased thirst, impaired thinking, and bone fractures.