My daughters diaper rash is hurting her

She’s crying and crying. She’s never cried like this at night before going to sleep but she won’t stop crying. Idk if I️ should take her to the er. I’ve tried so many diaper rashes for her and none seem to work. I️ feel so bad for her . She doesn’t even want to sit down. ( she’s a one year old btw ) she also has diarrhea idk if that helps anything but I️ keep having to change her diaper way more often and it hurts her even more 😰 please help me