What Causes Irregular Periods And Idiopathic Intracranial Hypertension?

I have had irregular menstral cycles for the past year to 18 months; i.e. missing some months and bleeding upto 3 weeks other months, along with pain in my lower left pelvic region that refers to my low back. I have also been diagnosed with IIH last November and now taking Diamox 1000mg a day. I'm 31 years old, 6 feet tall and 140lbs.
Could my irregular cycles be causing the IIH and what are my options besides birth control to maybe help reduce or reverse both issues?