tips on how to soothe a baby who cries for hours

Jessica
Please help. My three week old daughter screams ALL NIGHT LONG. I don't know what to do. Nothing is wrong with her. She's been fed, burped, changed, swaddled, cuddled, her binkie is in her mouth (she's quiet right now but is WIDE AWAKE), she's had a bath to try to calm her and help with any gas she might have, been cuddled and kissed and held and sang to, talked to, read to. She just doesn't stop. I have never seen a newborn baby stay awake like she does!!! I can't get anything done, she was in the NICU for 2 weeks so I started pumping (she refuses to latch) and my milk supply has decreased because I can't pump and tend to her needs. She has pretty bad diaper rash so we try to keep her changed as soon as she poops. But she poops sometimes 3 times an hour. If not more. So between that and everything else it's hard for me to pump. If I let her cry she makes her self so upset that she gets sick and then gets even more gassy and miserable. Please help. We have tried gripe water, gas drops... and my friend is sending me the gerber soothe probiotics to try and see if I like them or not before spending the money on them. I love her, but she is wearing me out.