we had a similar problem with my daughter at that age. she always came into our bed for half the night and screamed to get out of her cot. on the advice of the sleep clinic we put a stair gate at her door and dressed her warmly in a fleecy sleepsuit. she had a futon in her room near the door and she would always eventually crash out on the mattress. although we had a few tears,they didnt last long and we knew she was safe and warm even without her covers.i had always disapproved of controlled crying but in the end we got really desparate. it wasnt nearly as bad as we thought it'd be. good luck!