nappy rash

Cindy💕 • 18, mummy to George 31/07/16👶🏻💙 fiancée of a amazing man 5th Jan '16💕
For the past 4ish days my 16 week old has had awful nappy rash, I've tried sudocrem and metanium, I stopped putting any kind of bubble bath in his bath, ive not changed nappy or wet wipe brand, anyone help me with how to clear it up?