Struggling night nurse

Is anyone else struggling with nausea during the night shift? From 1am- when I get home and go to sleep I am nauseated! I have tried unisom and b6 together as my doctor suggested and it's not helping at all. I'm not sure if it's because I'm tired or just that time of night. I don't really have a hard time on my days off during the day, but nights are aweful! Could it be stress too??? I am an ICU RN... It is stressful a lot but it doesn't usually bother me I didn't think. Help!