I read your longer post, too and it sounds like you have a very severe situation. Please take note: you are not alone. I have been working as a researcher for the past two years learning about headaches, their causes, triggers, and alternative prevention methods. Extreme sleepiness before a migraine is a common early symptom, or "prodrome". Although you don't get auras, you get the earlier phase warning you of an oncoming headaches. Some people have increased yawning, others crave certain foods of have a decreased appetite, some people might feel cranky or tired and sluggish, and these symptoms can occurs anywhere from two hours to two days before your headaches. In addition, it sounds like you have "postdrome" symptoms as well, these happen after your migraine and can be very similar to how the prodrome feels. Some examples are feeling tired/sluggish, or experiencing mood changes.
One of the things that we have been working on for our research is the development of a headache diary to be used as an app on the iPhone. This can be very helpful in noticing trends related to your headaches, such as identifying triggers, or common symptoms. If you are interested in testing out the diary, you can sign up for our free research study at www.crfh.ca/whi (Please note, permission has been obtained for posting this link). This may help you to notice what usually happens before you get your headaches, or to track how you feel and how you sleep after your headaches have finished.