I didn’t see your post soon enough to tell you, but I knew exactly what had happened to you. I had the same thing. That was several years ago, and I am still prone to the same problem. That was one of the 3 migraines I’ve had in my life and it was absolutely excruciating. You need to make sure you are not arching your back which will put pressure on your neck. I prop my feet up so I can’t press off the floor.