Help! Lately my son has been staying awake til 2am despite our best efforts. Tonight he actually let…

Help! Lately my son has been staying awake til 2am despite our best efforts. Tonight he actually let me get him to sleep by 9:30pm (his normal bedtime). Now he has drunk 3 full bottles between 9:30 and 1:30 (usually drinks 1 bottle every 3-5 hours). He is also crying a lot in his sleep like he is having nightmares. He has had Motrin as he is teething. Cluster feeding? Thoughts - and go!