Yes, this often happens to me and it’s a common phenomenon in ketosis. The main recommendation seems to be to drink (even more) water.
But I would also be careful with your electrolytes – you likely need more than ‘a bit’ of salt, and potassium and magnesium are also crucial. I can just about get through 4 days without electrolyte supplementation but there’s no benefit to depriving yourself of electrolytes and I certainly wouldn’t push it beyond 4 days.