My 7.5 months old started waking up crying/screaming during sleep since few days.. this is usually for day time naps.. and at night she is just fussy. When she wakes up she is all trembling and screams like scared, it is usually difficult to calm her up during that time even when she keeps eyes wide open but after a few minutes she will either go back to sleep or will be fine. I don't know wether this is due to colic or anything.. ?