My 9 month old baby is usually fine at going to sleep in the evening. Over the past week, she protests much more at being put down and then once she's asleep, will suddenly wake and start crying / screaming with no build up, just a sudden burst. Sometimes she can be soothed in the cot with some back and head rubbing, but sometimes she needs to be held. Even then she thrashes her head around and pulls a lot at her right ear. Could this be an ear infection? Separation anxiety? Something to do with trying to start crawling?