PLEASE SHOW ME THE WAY😫😩

My son is 6 months old and will be 7 months old on the 18th. I have tried everything to try to get a routine going and it always fails. My son does not go to bed until 3 or 4 in the morning!!! It gets so bad sometimes that I want to rip my hair out. My SO goes to work at 8 AM and doesn't get off until 6 and I stay at home. I feel like I don't get enough sleep, I forsure don't eat enough and I have become anti social from being so exhausted! My son is so used to this schedule that it would be hard to change but I need to. I feel like a walking zombie sometimes that is stressed out passed 100. Us there anyway of fixing this? TIA!