Oh darl it sounds like you and DH are doing it incredibly hard at the moment so big hugs first and most importantly. I'm having the same battles with my little man at the moment so I'm not much help but can share what I'm trying. THrough the help from ladies on here I worked out that he was overtired and so each sleep was getting worse. My DS is 5 months old so a bit younger but he is only up for 1 to 1 1/2 hours max. He was screaming whenever he was in bed so I was having to hold him until he stopped screaming and settled down and went to sleep which was taking hours. Now that I've got him into more of a routine of feed/play for up to 1 1/2 hours depending on his tired signs he is settling much better and now that is flowing through all of his sleeps and he seems to be correcting them himself.
Can I ask how your day/routines are at the moment?