Could just be an AF symptom. I know I have had months when AF is here and it has made me nauseous. A few years back I had AFs where I would pretty much pass out.
Have you ever been tested for anaemia during your AF hun as i had this a few years back. It made me sick, light headed and faint and just drained. I went to the docs and got iron tables to take a few days before AF was due until a few days later and they seemed to help.