Hello Lisa,
Welcome to this forum!!
Ouch, falling off of a horse can be serious as you now.
I'm glad you are going to your doctor tomorrow. Only wish you had done so the day after your accident. Make sure you doctor takes some x-rays.
Do I assume correctly that you will be going to a GP/PCP doctor? If so, I would highly recommend that you make an appointment to see a spinal surgeon to get his/her advice. Don't delay. Time is important.
I do hope all will be okay.
RichT