Sleep HELP

I have an 8 week old that doesn't sleep during the day! He will fall asleep on and off during a feed for about 10 mins. At night he sleeps around 8pm-12am then will dose off after a feed and I have to keep patting his bum for him to stay asleep until 3am has a feed and have to pat his bum again until 5am. I struggle to keep him happy during the day unless there is a bottle in his mouth, he doesn't really drink just sucks it. When did your babies start to sleep during the night and have naps in the day? What can I do to keep him happy, I walk endlessly around the house, play music etc I just thought newborns slept like 14 hours a day haha.