Any ideas how to get bub to self settle/resettle?

Hi all! I'm just wondering if anyone has any ideas on how to get our DS to self settle/resettle at night without doing controlled crying?

We've had troubles for a long while (basically his whole life) with his sleeping and while he sometimes resettles himself at night, the majority of the time he doesn't. I don't know if he's just having wind/tummy/teething problems on those times he won't resettle (he arches his back/pulls up his legs and screams) or if it's just that he misses us etc.

We've tried controlled crying when he was tiny and again recently but it's just not good for any of us...he screams like he's being dragged over hot coals and that goes on for as long as we keep trying...then he takes ages to settle down and sobs for another hour or so. It's heartbreaking...I know we should be stronger but I just don't think we (any of us) can do it...

Is there some other way to teach him to self settle? He's really easy to get to sleep if we sit with a hand on his chest for a few minutes but hates if we leave the room. I'm not sure if that's one reason for him waking at night but like I said, he CAN resettle himself sometimes, if he doesn't have that painful scream thing going on.

Any ideas??? Thanks in advance! :)