No appetite and breast feeding

I've literally had no appetite for days and I'm breastfeeding.Is it just me or is anyone else experiencing this? The only thing I've ate all day is pretzels and a very small piece of pie sometimes it's nothing or even less then that. I just feel like puking when I eat and I've felt sort of down lately. I was wondering will it affect my milk or will it take from my body? I hope it takes from my body bc I want what's best for my baby.