Separation anxiety anyone?

Hi all - our little girl has been thee perfect sleeper since she was 8 weeks old. We’ve never had a problem. She went into a big girl bed at 18months and we were always able to put her in and walk away no problem. For the last two weeks it’s like I’m dealing with the exorcist!! She won’t even lie down if try and leave the room. Wakes up all night and will only settle if I’m lying on the floor. We’ve tried letting her cry it out but she gets worse and worse. Has this happened to anyone else, will it pass or do I need to try something new?!

A very tired mum!