I don't really have any advice -
DS is nearly 2.5 and we sit next to him of a night time to get him to go to sleep. If he has a day sleep it can take up to an hour to get him to go to sleep (usually around 9pm). If he doesn't have a day sleep it takes about 2 minutes to get him to go to sleep..
LOL
But we have always sat next to him, just seemed to be what he needed at the time.