apologies for the delay in responding..
One thing of note, Excedrine is well known for rebound headaches, I am not clinical, but I would guess, that was the 4 day pain..
I spent some time on the migraine site I browse. There is not a whole lot of information on treatments.. where this discouraging, I would not give up hope..
I URGE you to talk to your doctor about
these headaches, there are medications that help and reduce or stop the pain.
Also I have added a link for your info.
www.mhni.com/headache-pain-faq/unique-neurological-conditions/hypnic-headachesPeace
Trina