Leah,
Wow, what an ordeal!
The bottom line is that you absolutely need a diagnosis and appropriate treatment. Whiel your symptoms do sound like Migraine, they could also be stroke, TIA, or any number of other issues. If they didn't run an MRA and MRV in the hospital, that may need to be done to fully rule out stroke and TIA. If this does turn out to be Migraine, there are treatments that can help.
If your doctors aren't coming up with any answers, I suggest you see a Migraine specialist. If you need help locating one our directory of Patient Recommended Specialists should be helpful.
I wish there were more we could do for you, but the first step is getting a diagnosis.
Good luck,
Teri