Awake at night

Hi! I have a 7 week old boy who just can’t seem to stay down at night. I was up from 10pm to 3am trying everything to put him to sleep. At the moment he loves sleeping during the day. He can take naps of about 2.5-3hrs with feed and play of an hour in between. I’ve cut his sleep and wake him up at max of 2 hrs because he was just so restless after his last feed and I was up for hours till the morning ams. I still am… how can I get my baby to sleep longer and better at night? HELP PLS.