Our little boy is just 12 months old and used to go to bed about 6:30/7 every night and sleep 12 hours. Nothing has changed in his routine (bath, bottle, bed) but he has changed completely in the last few weeks. He will not sleep unless one of us stays with him and cries continuously when he is left in his cot on his own. He used to be a little angel and we just want some advice on what may be causing this and how we get him back to how he was. We have tried leaving him (even though we hate to hear him cry) but he just gets more and more distressed... HELP!