Please help

My son is 6 months old & for the past week he has been waking up at 11pm & staying awake until 2am. I recently went back to work and leave the house at 3am so I’m not sure if this has something to do with it.

No matter what I try he stays up & thinks it’s time to play. I feed him & he just doesn’t go back to sleep. I rock him, I do everything. His dad & I don’t know what to do because this is very tiring for me as I work so early & it’s causing fights between me & my boyfriend because we are just so tired.

Please please someone help this is so difficult. I’m a first time mom & only 21 years old.