I have to question your assumption that it's ITBS. That often manifests as pain on the outside, not inside, of the knee. That's where i felt it FWIW. While it can cause hip pain, knee pain is much more common. So the site of your pain, along with the fact that it's radiating down your leg, makes me wonder. Now what kind of injury IS more likely, I don't know. Perhaps Wahine will weigh in.