Why is the hangover not as bad if I stay awake and sober up a bit before going sleep?

If I go to sleep whilst still drunk, the hangover anxiety is always absolutely excruciating all day, even if I drink tons of water, the hangxiety is just awful as well as the general dirty feeling, why is this? Is it because whilst awake my metabolism is faster and I can clear the alcohol out faster compared to if I go sleep and my metabolism slows right down?