3 year old won't sleep

[thecraftyfox]

Hello. I'm desperate. My 3 year old daughter will not go to sleep ever in her own room. She screams, cries, gets ot of bed and stands at the top of the stairs screaming and shouting for me, will hit her dad if he takes her back to bed.
When she does fall asleep it's on the floor and between 2 and 4 am she comes into our room. She says she does not like her bedroom, that she is lonely and that a scary lion comes in her room. She is still in a little cot bed but as we've just bought a house she is going into a full size single in a new bigger room after Christmas.
We're desperate for sleep, all of us and the sleep problems are putting my husband and I off ttc a second child. She's slept through twice since birth and I'm so broken.