19 month old not sleeping

Help! My little girl 19mths. Was sleeping thru the night 730-7 no bother and going to bed awake and falling asleep herself. The last 2 weeks straight she won’t fall asleep herself and wakes multiple times In the night and cries for ages. Nothin wrong as when we pick her up change nappy give her water give her even some pain killer and she falls asleep in our arms. It’s when we put her into cot she gets straight back up and roars. We are at the end of our rope! Please any advice. We have done cry it out and she has vomited all over herself from crying so much.