Not at birth weight..

Baby is 13 days old and has been breastfeeding like a champ. But at the first check up he had lost a lot of weight.. mainly from the transition home. We went back for another weight check 2 days later and he gained almost 8 ozs. Now a week later he’s at the same weight, hasn’t gained or lost. We’re still 6 ozs from birth weight. I feel so defeated and cried the whole way home. It seems like we have a good thing going and that he has gained weight, it’s just not showing on the scale. I feed on demand but won’t let him go more than 3 hours with out eating. He’s almost too big for newborn clothes and diapers and Has the appropriate amount of wet/dirty diapers. The nurse said to increase feedings to every 2 hours from every 3 like we are now. But the kid won’t wake up. Any other suggestions? TIA