I had a horseback riding accident and fell on my back pain is spreading?

Q: Hi my name is (…) i am 21, I had a horseback riding accident last week, and fell on my back, i do not remember how or where exactly i fell. The pain is located in the lower back. It was not bad at first but has grown stronger over the past few days, I have tried resting it but that has not helped either. Now the pain has been spreading down the back of my right thigh. It has been hurting when I stand, bend over, drive the car, carry my school bag, and anytime i lift my legs, or sneeze, I have trouble getting out of bed and walking . I would like to avoid getting xrays if possible since I had a similar accident 4 moths ago and sprained my lower back (or at least thats whats written on the doctors report) the pain then was much different from now. Can you please help me.
Thank you.

Medications: levothyroxine– after complete thyroidectomy in February