I have an infection from a fall on my scalp. What's any easy way to cure it?

Medical evaluation. Maybe necrotic tissues that needs to be debrief ed and closed.
Scalp infection. See your fp/pcp for evaluation & treatment. If there is a laceration/cut of any size that won't stay closed, it's usually best to have the wound tended to right away (sutures). When was your last tetanus booster? Remind the doc of any meds (rx & otc) & supplements you're taking & whether you have any drug allergies.