Adjustment Disorder with Anxiety: Given the patient's symptoms of anxiety and panic, and considering her high BMI which might contribute to social or psychological stress, an adjustment disorder with anxiety is a plausible diagnosis. This condition is characterized by the development of emotional or behavioral symptoms in response to an identifiable stressor, which could be her weight-related issues or other life circumstances.

Major Depressive Disorder (MDD): Anxiety and panic can be symptoms of MDD, especially in individuals with significant life stressors such as obesity. The fear of living could be related to feelings of hopelessness or worthlessness.
Panic Disorder: The patient's reports of panic suggest this could be a primary condition, especially if the panic attacks are recurrent and not better explained by another mental disorder.
Social Anxiety Disorder: Given the patient's high BMI, social anxiety could be a significant factor, leading to fear of social or performance situations in which the person is exposed to possible scrutiny by others.

Thyroid Disorders (Hypothyroidism or Hyperthyroidism): Thyroid dysfunction can cause anxiety, panic, and significant changes in mood. It's crucial to rule out these conditions due to their potential to cause severe symptoms and the importance of early treatment.
Pheochromocytoma: Although rare, this condition can cause episodes of panic, anxiety, and fear due to the sudden release of catecholamines. Missing this diagnosis could be life-threatening.
Cardiac Conditions (e.g., Arrhythmias, Coronary Artery Disease): Anxiety and panic can be symptoms of underlying cardiac issues, especially in individuals with risk factors such as obesity. These conditions require immediate medical attention.

Neurological Conditions (e.g., Multiple Sclerosis, Tumors): Certain neurological conditions can present with anxiety and panic as initial symptoms. While rare, these diagnoses are important to consider, especially if other neurological signs or symptoms are present.
Adrenal Insufficiency: This condition can cause a variety of symptoms including anxiety, and while it is rare, it is crucial to diagnose and treat promptly to avoid adrenal crisis.
Wilson's Disease: A genetic disorder that leads to copper accumulation in the body, which can cause psychiatric symptoms including anxiety and panic. It's rare but important to consider in young patients with unexplained psychiatric symptoms.