My baby is 1 week old and 2 days and I'm currently breastfeeding him, he tends to sucks for about 2 min then let's go and begins to cry because he is hungry. I try to calm him down because  breastfeeding a crying baby is complicated, but doesn't work. He latched on very well in the beginning  and all of a sudden he is not doing so well, it takes me forever to feed him because I have to keep putting it back in his mouth every 2 min. Has this happened to anyone before?