3mo th old turning head down while nursing

The past couple of days my LO latches and sucks for maybe 1 min before turning his head down towards my lap, sucking again for ten seconds or so then coming off. He will relatch but do this over and over. Have tried burping him etc. He had plenty of wet diapers but no dirty today. He does this on both sides and I've tried football and cradle hold, he never liked the lie down nursing. It hurts! And I'm worried he isn't getting enough. Any advice?? Thanks