Kids sleep is gonna make me breakdown

I have 2 kids- 4.5 boy and 2 year old girl. My son has always been an early riser but we got him sleeping till 6:30-7 at some point. Him and my daughter are now back to 4:30 am. I’m truly exhausted and don’t know what to do. If they wake at that time they are up for the day. I have hatches, sleep clocks NOTHING WORKs. 2 year old naps 1-1.5 hr at daycare and goes to bed at 7, 4 year old does not nap and goes to bed for 7:30. Does anyone have any tips? This is slowly breaking me down.