Out of the ordinary sleep tantrums

Hello, my daughter is 16 months and she's had a good and regular sleep schedule for some time now. 

However for the last couple of days every time we take her into her room to try and put her down (which usually we could do with a bottle, dummy and no problems) she freaks out, screams and tenses up her body. We try to Rock her until she's a bit sleepy then put her down but as soon as we put her in the cot she cries and gets up?!? 

Last night she was up until 12am just sitting with me because she just wouldn't go in her cot. Even tried to lay her with me in my bed, but no luck.

I've tried just leaving her in her room and closing the door in hopes she will eventually fall asleep but this hasn't worked either. 

Shes not really eating properly either and shes teething quite badly so not sure if this anything to do with it. 

Just putting this this out there because her behaviour has changed so dramatically over the past few days. Not sure if it's nightmares or what. 

Any advice or suggestions? 

Thank you