9 week old daughter won't stop crying

Sa

My 9 week old daughter won't stop crying, I've fed her, and changed her nappy and burped her. I don't know what else to do. She's been like this for the last two days. She has a rash which we took her to the ER they said it was eczema but I'm not 100% sure if that's what it is. Anyone else have this problem. What do I do??