My shin hit edge of stairs. I got wounded and the bone hurts a lot. How to cure it fast?

Depends. Shin trauma is a most painful injury. You have my sympathy. Time to healing depends on the severity of the damage, with fracture being the worst (approx 6-8 weeks) & bruise being least (approx 1-4 weeks). Time to pain relief requires close communication with your clinician if you are still having a lot of pain. Hope that helps. .