before bed force yourself to drink a shit ton of water, 1-2 liters, and take a multiday vitamin with that. every time ive taken a vitamin before sleep, the next day hangover is reduced by like 3x.
also you could go to a vitamin store shop whatever there called and they sell hangover cure pills, just a pill with a bunch of natural ingredients. ive bought a few different kinds, some work, some dont, you just got to test them out.