3 year-old bedtime fears - any suggestions?

We have a 3 year-old (3 years 3 months to be more specific) and a 9 month-old. A few days ago, the 3 year-old suddenly became afraid at bedtime. It's not a fear of the dark I don't think, because we've wound up leaving the lights on in her room.She wants us to watch over her, and the first night this happened she was hysterical, constantly climbing out of her bed and doing anything she could to not go back in. I wound up sitting just outside her door where she could see me and she calmed down and went to sleep. The last two nights I've done the same, and I notice that she keeps checking to see if I'm still there before falling asleep. After she falls asleep, I go back to my room, but around 1 a.m. she has woken up, realized I'm not there, and starts freaking out again - and I've wound up back at the door (eventually just passing out on the floor).Has anyone experienced anything similar to this, and what they did about it? Does this seem like one of those things we just ride out and let work itself out over time? I want to make sure she feels safe and not afraid, but I'm also worried about creating a crutch where she needs someone at the door, and making that part of a routine that she expects. Also, my back hurts from falling asleep on the floor..Any pointers/thoughts/suggestions/advice would be greatly appreciated! via /r/Parenting http://ift.tt/28Z5dFQ