I have had frequent urination for 7 months and it has been severe. what is this? and i urinate large volumes of water even thought i am dehydrated.

Possibilities: Symptoms suggest possible urinary tract infection (especially if there's burning & pressure sensation or blood), diabetes mellitus (especially if accompanied by hunger & thirst, poor healing, loss of feeling/burning sensation in feet), diabetes insipidus. See your doc for evaluation & treatment.

Have to be checked: When patient present those could be abnormality of diuretic hormone, vasopressin, insipida diabetes, sodium, others electrolyte, kidneys .Please see a physician

DM,OAB, IC, UTI: Hope you had a urinalysis. Possible explanations apart from your consuming moor liquids is ? Diabetes, overactive bladder, interstitial cystitis, UTI or bladder or urethral polyp, or brain tumor affecting secretion of antidiuretic hormone. (latter two are very rare).