What do I do if I have diabetes insipidus?

Follow doc's advise. You need to find out the cause so you can be treated appropriately. Often time, diabetes insipidus is just a symptom, not the cause. The hormone involved is ADH (vasopressin) (antidiuretic hormone). If the cause is in the brain, treatment is to give back ADH (vasopressin) (ddavp) either in nasal spray or pill. If the problem is at the kidney, treatment is antiinflammatory (indomethacin) and diuretics (hctz and amiloride).
See your doc. I am not sure how you know this is what you have, but if so you need to see your doc for treatments..Two types: one is deficiency of arginine vasopressin (a diuretic hormone--avp) and other is nephrogenic (kidneys not sensitive to avp). You will/should find out why having diabetes insipidus. But either way, you still will need treatment. Consult your doc... Good luck.