I Was Told I Have Bulging L4-5 L5-S1 - Moderate

I was told I have bulging L4-5 L5-S1 - moderate stenosis before Christmas. Diagnosed using CT scan. Have been waiting for an MRI since December 15. My back feels ok now. I have excrutiating numbing pain down the back of my left leg hip to mid calf and cannot straighten my leg. This has only begun 3 days ago. No swelling, no discolouration, just pain down the back of my leg any ideas??