Newborn problems with feeding

Hi, I’m a first time mom and my baby is a week and a half old and up until yesterday he has done great with breast feeding. He normally wakes up to eat every 2-2 1/2 hours and nurses for about 13-15 minutes each side. But yesterday he started having shorter and shorter feedings and he will just stop drinking and nothing I can do will make him drink again. He’s done to 5-10 minute feedings and he’s starting to sleep past his feeding times. Last night he slept for almost 5 hours without waking up to feed, which is just making me more worried. Am I doing something wrong, why is he all of a sudden not drinking enough. He’s still having at least 4 dirty diapers and 7-8 wet diapers a day. And he’s not super sleepy all the time either, sometimes he’s wide awake and not fussy at all but just refuses to drink. What should I do? And does anyone have any advice?