Super hungry and nauseous

I’m breastfeeding my baby and it seems like no matter how much I eat I’m just always hungry. It’s to the point where I’m just tired of eating but I’m still getting hunger pangs and my stomach won’t stop growling. If I don’t eat enough (idek how much is enough) I get unbelievably nauseous. I’m not pregnant (we checked already) but I almost feel like I am with how nauseous I’ve been so constantly. Is anyone else experiencing this with BF? Baby is almost 4m pls help!