Nausea for 4 days after 24 hour stomach virus...?

I got the stomach flu or a stomach virus on Sunday 12/12 and I am still experiencing intense nausea after 4 days of having the virus. Is it just the virus leaving my body? I also, unfortunately, started my period on Monday 12/13 so it could also be contributing to the nausea. The nausea is usually worse in the mornings and if I lay around all day it gets better, but today it's been all day. I know I should eat, but everything sounds so gross. I've had half a bagel and a pop tart today 12/16 (day 4 with nausea). I hope someone can help. Thanks!