Diaper rash with vengeance

What is a good diaper rash regimen? My son is bleeding and so red on his genitals. I took him to dr 3 days ago and it’s not getting any better. I did just what he said and still no improvement. I changed the diaper. Baking soda treatment. Aired him out. He walk like his hip hurt. I called him and he said it take time. I’m like bullsh**

Help me please. How can I heal him?!!!