Welcome!!! I am so sorry that you are struggling with this intractable migraine. I have had really bad "episodes" like this and I am trying my best to think of something to tell you that you haven't already tried. I have been through the hospital stay with multiple medications which my doctor and I finally found the right "cocktail" that works (it was by no means an immediate thing)
Please call your doctor and dont take "no" for an answer. If they can't squeeze you in go back to the ER! I have to say that kind of pain wears you down physically and emotionally.
Do you have a headache specialist nearby?
I wish I had an solution for you!!!
Please let us know how you are doing.