4 year old not sleeping

My middle child is getting up every single night multiple times a night crying or saying she doesn't want to sleep in her bed. This started when we switched her out of her toddler bed to a twin 2 months ago. Everything else about her room and nighttime routine is the same. Prior to this, she was an amazing sleeper. Always went down easy and slept all through the night 95% of the time. Since this started she's either been sleeping in our bed or I'll sleep in her bed, this is so she doesn't wake up my other kids and cause more problems and tears. When we sleep with her, we dont get any sleep because she is the hash slinging slasher in her slumber. I've never seen a person move so much in their sleep. I'm at a loss. I keep asking her what's wrong about it and she says she just wants my bed. She says she's scared. I've tried everything from night lights, to melatonin, to bribery. Any advice? I can't do this anymore. I feel bad that she's losing so much sleep too.