With all the caveats of don’t do anything you or your doctor don’t feel comfortable with, but for what it’s worth I used one of those hydration IV places that cater to hungover people. They’re a bit expensive (around $80 and up near me) but cheaper than a trip to the ER if you’re getting too dehydrated. Your drs office might also be able to give you an infusion if you need it and insurance might cover it that way (it’s worth asking at least).