4 month sleep regression ...

Anyone else’s LO hit the 4 month sleep regression?? My little guy from about 6 weeks old slept from 9pm-5am. Then about a month ago we got him to 8:30-5am. Well the last week he’s been fighting sleep likes crazy. He still will go to bed by 8:30 but the last two days he’s woken up at 3:30 on the dot crying and it takes me about 30 min to get him back to sleep then up at 5 to eat. And then back to sleep until 8am. I start back to work this week...and after 2 nights I’m already exhausted😬