my baby is 4 months old, and he only wants to sleep on my lap. when I put him to bed he wakes up and starts crying. he only sleeps on bed at night time and that long sleep also gets distracted after 3-4 hours, He starts crying even if I feed him. at day I can't even do any work for his constant crying.. he just wants to stay on my lap..how to fix this problem?? and he sleeps very less, hardly 10-12 hours a day.