What Causes Chronic Headaches,muscle Weakness And Palpitations?

I am a 32 year old female, 5'5" 200 pounds. I have been experiencing a wide range of symptoms for years but they became worse during my pregnancy last year and have gotten worse yet after delivery. I have chronic headaches including migraines, musle weakness, heart palpitations, fatigue, swelling. I have been diagnosed with mitral valve prolapse with regurgitation, migraines, and the report from the endocrinologist said I show classic signs of Grave's Disease although no thyroid antibodies are present. Thyroid nodules appear to be benign. TSH levels are elevated with normal T3 and T4. Slightly elevated white blood count but of no concern. I want to know if any of this could be related to a possible pituitary gland disorder.