Thank You. My 28 Y/o Son Is Bipolar, And Also

Thank you. My 28 y/o son is bipolar, and also has Type II DM...on 2000mg of metformin daily, and Victoza 1.20 daily. In July 2016, he was working in a restaurant kitchen and suffered dehydration from sweating, and lithium toxcicity. The ER sent him to a city hospital because the nephrologist thought that he may need dialysis. Thankfully, he recovered with copious amounts of IV fluids. Lithium was stopped. He is still on 75mcg of Synthroid because his labs indicate slight hypothyroidism, even though it was originally prescribed because of the thyroid suppressent effects of lithium. He just recently discontinued Lisinopril because his nephrologist and endocrinologist said it is unnessecary. (He was originally put on it for renal protection from the DM). Since he was ill in early July, he has been weak, unable to work, had a three day episode of Bell's Palsy (Lyme titer negative). He also has constant episodes of cold intolerance, then sweating and cold chills. He wakes up drenched in sweat. He also complains of light sensitivity, which was very acute when he had the renal issue. I don't know if it related to adrenals, thyroid, diabetes (last A1C 8.1). Labs are normal except for high triglycerides (600+). He is 56' tall, and weighs 227 (down from 252). I don't know if I should start with his nephrologist, endocrinologist, psychiatrist, ??? He takes 200 mg of Lamictal a day and 4mg of Risperdal for bipolar. I was thinking mononucleosis, perhaps? The other meds he takes are 40mg of Nexium a day, and Fenofibrate 200mg a day. His BUN and creatinine are within normal range. His appetite is good, but he has several loose bowel movements a day, with urgency. Any advice would be greatly appreciated.