My girlfriend has eczema, how can I help

My girlfriend has been dealing with eczema all her life. Recently she has been experiencing more flare ups than normal. She wakes up in the middle of the night itching and crying due to discomfort (mental and physical). She wakes me up and asks for my help but I don’t know what to do to help her. If anyone has any tips I would appreciate it.

And if I may ask for someone’s opinion/advice, is it understandable for me to loose my cool after she starts to yell at me when I don’t immediately do what she asks me to do? Or at least how can I handle this

(Ex. She tells me to get her lotion and then to turn up the AC. As I’m looking for the lotion in complete darkness without my glasses I try to turn on my phone’s flash but she yells at me that it’s too bright and she doesn’t want to see her skin. Then she gets upset and demands for the lotion. Then demands and yells to turn the AC on. At this point I am tired of the yelling and start to get upset at her and then I might yell back which will trigger her even more)

Thank you for anyone’s help in advance