Help!! Breastfeeding/formula advice??

Ok so I have a two week old who constantly needs to eat. Constantly. He never seems full!! Today, I fed him multiple times and he didn't fall asleep right after like he had been doing in the past. My husband and I decided to give him a sample of formula we were given by my doctors office and he passed right out. Also, if I try to pump I get barely anything. Today, after pumping BOTH breasts, I barely had 1 oz. could my supply be lessening??? Should I try to supplement? Im going to ask his pediatrician at his appointment next Thursday/see what his weight is but I just wanted a little insight if possible. Thanks!!