help please?

Cindy💕 • 18, mummy to George 31/07/16👶🏻💙 fiancée of a amazing man 5th Jan '16💕
My 6 month old keeps waking up between 4 and 5am and will refuse to go back to sleep and will cry and scream until we go downstairs and play, how can I stop this? 1 extremely tired and stressed mummy here