sleep deprived!

Ruth
My baby has just turned 6 months old. She used to have a "dream feed" at 23:00 and then sleep until 7:00. With teething this has now changed, she goes to bed at 19:00 and then is wide awake at 23:00 after she gets her dream feed and will not go back to sleep! Any tips would be appreciated as I want my sanity back!