Nauseas during breastfeeding?

Has anyone experienced nausea during breastfeeding? If so, how did you keep it at bay and/or eat enough? Anytime I nurse or eat I feel like I'm going to be sick and it lingers all day but peaks then. I'm having such trouble eating I lost the 30lbs I gained in less then 2 weeks from giving birth (dr is aware and not concerned). I'm mostly concerned about my milk production being low and am hoping to increase intake to increase output but don't know how. Yesterday I could barely eat 1/3 of a frozen meal (and almost didn't keep that down). Thanks!