New Symptom Sudden Extreme Sleepiness

This past Saturday till about yesterday evening I battled a migraine. The pain was enough but not enough to prevent me functioning. Just a drone of a migraine that hammered though. Last week up until yesterday I had ringing ears and somethings I "think" I saw things that were not there like colors etc. My main concern is last Thursday while at work I found myself suddenly having the inability to keep my eyes open and remain awake. I was sitting at my desk sleeping and typing away, with all my strength I could not snap out of it! It seemed like hours passed while I was out cold but of course it was only minutes. I am sure coworkers saw me but said nothing but since I was still moving I guess they might have thought I was awake since I had not fell over. This type of episode did happen last month but I don't think I had a Migraine come about. I did have the usual nausea I get for most of the month that builds to a cycle comming. Anyone else experience something like this?