Hi, thanks for asking in Healthcare Magic.
Diabetes mellitus often presents with symptoms of excessive thirst, increased appetite (weight gain) and increased urination. Your dryness is because of excessive thirst due to
frequent urination and the resultant dehydration. Weakness and dizzy spells occur frequently in early stages due to uncontrolled or un diagnosed Diabetes.
Another cause of excessive thirst, dry mouth and increased urination is
Diabetes Insipidus due to improper secretion of anti diuretic hormone, that regulates water excretion.
Urine test for the presence of sugar in urine, Fasting and Post Prandial blood sugar values and oral
glucose tolerance test will confirm Diabetes mellitus. If it is negative then you should undergo
Desmopressin test, done to diagnose Diabetes insipidus.
In case of Diabetes mellitus, weight reduction will improve the action of insulin in the early stages. If the blood sugar values are not controlled by weight reduction alone, then you will need anti Diabetic drugs like Metformin to control Diabetes.
i hope this is helpful to you.