Hello,
Since you had a  fall from horse back, you should get clinically examined by an orthopedic doctor. Get X-ray, CT / MRI done to detect any 
fracture bone, torn ligaments / tendons, or any internal injury. You will be treated accordingly. In the meantime, do not stress yourself. Stay at rest. Avoid addictions if any. Take NSAIDs, 
naproxen or 
Combiflam, one stat when needed to ease pain.
You can apply a thick layer of ointment Thrombophob (benzyl nicotinate and 
heparin) to reduce inflammation, swelling or any 
blood clots below the skin that is causing purple bruise. You will be at ease after the bruise reduces and swelling goes down. Do not massage. Stay away from addictions if any. Take care of your hygiene so that it does not get infected.
Take care. Hope I have answered your question. Let me know if I can assist you further.
Regards,
Dr. Nupur K., General & Family Physician