I have a chemical burn on my scrotum from using Nads hair remover. I did this about 7 hours ago. What should I do now?

Nature. Let it heal naturally. You may apply a small amount of an emollient like Vaseline.
Despite current fashion, removing hair from your genital area is unhygienic and not recommended.
For good health - Have a diet rich in fresh vegetables, fruits, whole grains, milk and milk products, nuts, beans, legumes, lentils and small amounts of lean meats. Avoid saturated fats. Drink enough water daily, so that your urine is mostly colorless. Exercise at least 150 minutes/week and increase the intensity of exercise gradually. Do not use tobacco, alcohol, weed or street drugs in any form.
Practice safe sex, if you have sex.