Hip/leg Pain- Please Help

I apologize for the length.

Here's my story:

on october 16th, I was in a wedding and required to wear some rather high heels. As we were leaving the church, it was sleeting and in an attempt to reach the limo without ruining my dress, I started running. As I was running, I felt this sudden, very sharp pain towards the back of my thigh, near where my hip and leg meet. The pain started to grow worse as time went on. At first, it was a very sharp ache when I walked or put weight on that leg. A day or so later, I started having trouble lying down or sitting. When i'm doing either, I feel this intense pain that seems to go deep into the bone. It almost feels as if my hip has been completely overworked. Along with this new pain came a numb feeling. It feels like my leg has fallen asleep and its very, very intense and almost unbearable. Two weeks after I started having these symptoms, I was stepping off of a stair and my leg buckled. That prompted me to go to the Dr.

My doctor ordered an x-ray, which came back normal, and then suggested a problem with my piriformis muscle and gave me exercises to do at home. Two days later, the pain was so intense (i started having excruciating muscle spasms that have since persisted) I called in for a prescription for a painkiller, which did absolutely nothing. I saw him again a day later and he again said it was the piriformis muscle and prescribed crutches to rest the muscle and physical therapy. He also gave me an anti-inflammatory and a muscle relaxer. The muscle relaxer doesn't really do anything aside from making me so loopy that I don't care that my hip hurts!

I started physical therapy on november 3rd. My therapy consists of ultrasound and heat therapy followed by a routine of exercises such as 5 minutes on an exercise bike and straight leg lifts, etc. On november 10th, I went in to my doctor and after hearing that therapy has done nothing to ease my pain, he gave me a cortisone shot. I reacted badly to the shot and the next couple days were the worst in terms of pain.

So, now it has been a month and the only benefit i've gotten from the physical therapy, shot, and medication is that I can walk for a longer period of time before I start limping. Nothing else.

Here's where I stand now:

i still cannot sit for very long, I cannot walk for very long, I cannot find a position to lie down in that's comfortable for more than 30 seconds.

I can walk but after more than 20 minutes I start to limp and at all times, there is a sharp pain at the top of my leg near my hip.

I do not have groin pain while walking but I do have it when doing the pt exercises that require me to pull my leg up to my chest.

The pain often shoots down towards my knees.

The intense numbness is almost always present.

I have been having a lot of very painful muscle spasms, some that last for a full minute.

The pain in the area of my piriformis muscle has started to stretch across the back to the other hip and I have been having pain shooting down that leg as well as the numbness. Not quite as much as the other leg but its still there.

I go for an mri on wednesday but I was hoping someone could shed some light on this. I don't feel its my muscle. The pain seems too deep for that.