....are you drinking enough water and what does your blood sugar look like?
A dry mouth for me is a sign that my blood sugar is elevated and since you report that particular symptom after "being bad", you might want to have it checked out by your doctor or borrow a blood sugar meeter (glucometer) from a friend and check it yourself. You can have normal fasting blood sugar readings but still have high readings after eating sugar or other sources of refined carbs.
If you do decide to check with a meeter, you would eat something that produces the symptoms and then check at 30 minutes, 1 hour and 2 hours after eating it to see what the readings are. Normal would be no higher than 140-150 at any point and below 120 at the 2 hour mark. If those are normal, then it's probably something else causing the symptoms. If they're not, you might want to make another trip to your doctor to have them follow up on it.