Diaper rash 😥

So my daughter has a pretty bad rash all on her inner thighs, private area & on her butt she screams every time I change her 😔. It’s the first time she had actual real tears 💔I just notice it today about a hour ago i change her every time she’s wet idk how she got one and this bad! I’m on the fence about taking her to her pediatrician. Husband says to just put rash cream on it. Idk what do y’all think right now I’m using baby Vaseline will this help should I use a different one or just make a appointment how can I ease the pain for her ? He doesn’t want me taking her in Bc of flu season and the sick kids there so if I can treat it at home that would be great! She will be three months at the end of this month. Picture of my beauty for attention🥰 any advise tips are greatly appreciated ! Tia