Severe Diaper Rash?

Ladies! Help! My 3 week old baby boy developed a diaper rash a few days ago we thought it was the diapers so i changed them and it didnt work i tried the buttpaste rash cream and it didnt work its gotten worse now. Idk ig its the diapers, wipes, or cream idk. Its bot as bad as before but its does look bad. He has an appointment later today but wanted to ask for some remedies you mommies know about?