I’ve always had a policy of eating well. I make sure I have a decent enough meal before I go out, and I eat before I go to sleep. It’s always served me well enough. Whether it’s a kebab, a pizza, or some other not that good for me meal it tends to do the job.
Hydration, as everyone else has said, is key. A friend of mine used to swear by the combination of Berocca and Dioralyte, which are UK products but isn’t far off what OP uses. Berocca is a vitamin blast you dissolve in water, and Dioralyte is an electrolyte powder that is meant for dehydration (marketed towards diarrhoea but dehydration is dehydration).
For the worst moments when none of that happened or worked, I used to be able to make myself sick in the morning, which is basically a reset button. When you get rid of what the body is struggling to process, it’s got nothing to moan about. You’re just left hungry. Problem is, that hasn’t worked as well the last couple times I’ve tried it, and I’m not sure if it’s because I’m getting older or because I don’t drink I like I used to.