My new little guy will only nurse for 7 minutes in a row. Like clockwork, he simply refuses after 7 minutes. He's two and a half weeks old and still not regaining the weight he lost, so my doctor says to do what it takes to feed him for 20 minutes each feeding. Help! How do I get him to relatch? (We are feeding on demand during the day, usually every 2 - 3 hours, but never more than 3 hours, and feeding every 3 - 4 hours at night - 3 if he wakes on his own and 4 if I have to wake him.)