We've messed up a 3 year sleeping. No clue how to get out of it.

So we co-slept with our son since he was born. Mother doesn't believe in cry-it-out method of sleep training. I am more willing to do some of that. The 3 year old has been getting better about sleeping through the night, but has never really done it consistently ever and has regressed a bit lately.Right now he is screaming for mommy who never really deals with him in bed, she's sleeping with the younger one. I keep telling him that I will lay with him when he wants to lay quietly but when I leave the room he screams at the top of his lungs. So I let him for 5 minutes and then go back in, give him a hug and ask if he wants me to stay and lay quietly.I don't think he is able to process my words because he is in a fit. What should I do? Just let scream until he calms down? Cry himself to sleep? via /r/Parenting http://ift.tt/2pgMoGG