You need to be eating something, I would definitely talk to your midwife or dr there is nothing to be ashamed about, they will help you! You can try medication short term (some are safe dwhen breasfeeding) I know it seems drastic but you are doing more harm to yourself by feeling like this and try drink milkshakes/protein shakes and just nibble on nuts/raisins if you can. I hope you feel better soon and remember it could get so much worse if you don't act now, just talk to a professional or even a friend, there are even helplines you can call anonymously to talk things through. It is so hectic been a new mum! I suffered from postnatal depression for a year after I had my daughter and it still flares up now occasionally.