It could be that you're eating less due to not feeling well and you might be dehydrated too. Make sure to avoid meds with pseudoephedrine and it should just be temporary.
med-free birth x2, breastfeeding, baby wearing SAHM My BFP Chart
Yes, it does. Make sure to stay hydrated and it should go back up once you're better. There were a couple of times with my son (right around 6 mos and then a couple of times after that) when I needed to use frozen milk to supplement while I was sick.
Re: Does milk supply go down when you are sick?
med-free birth x2, breastfeeding, baby wearing SAHM
My BFP Chart
I am on amoxicillin...