20 years old male 125 pounds 5 foot 5. lost weight 25 lbs over 6 months recently. blood work shows sluggish thyroid and moderately low vitamin d. all other results within normal range. EKG normal. nail bed blue hue showing oxygen levels low. When he started exercising he was not consuming enough calories. He started having issues with panic attacks, always feeling exhausted, never hungry, diarrhea often, not sleeping well, has family support system in place, is not depressed, good attitude, environment safe and well cared for, during panic attacks he feels that something is wrong but he can't put his finger on it. Panic attacks are happening daily. We have upped vitamins but don't want to go the direction of celexa. Please advise