i thought we'd started bf off quite well. he's gaining weight, sleeping well etc. but last couple of days he's fussing, pulling off, whinging and generally acting like i'm trying to feed him cat food or something equally gross. he latches on quite well, but then pulls off & starts pulling on my nipple, which is really starting to hurt. i'm burping him in case it's wind, not sure if is milk coming too quickly, but beginning to get a bit fed up now. any suggestions??