Ex-Race Horse Trust and calming help!PLEASE!!!?

Ground work, ground work and more ground work. Go back to the very basics that she probably never had, even at 19. She is probably just reacting with fear and a lack of confidence. It will take patience and time. I would not lunge her. I would teach her to go away from me and return, move left, right, forward and backward. Teach her to respect your space. Introduce lots of lateral flexion and teach her head down which is very calming as it shows tremendous trust from her. Help her to relax. Control her mind and you can control her feet. When you accomplish this on the ground, it translates pretty easily to under saddle. good luck