Baby won’t nap on his own

Sa

My 11 week old son will only sleep on me during naps. If I lay him down he wakes up within 20 minutes crying. If I hold him then he sleeps for 2-3 hours. I have spent several days truing to just lay him down and get him used to sleeping on his own, but it isn’t working and ends in him being overly tired and fussy by the end of the day. To top it off, he was sleeping through the night and is now waking up every 3 hours. Any advice?