The symptoms you describe of thirst and passing urine frequently may be potentially caused by several conditions and it is difficult to make a single diagnosis without more information.
Please review this with your physician who will be able to take a more detailed history, review your current medications, examine you and commece the appropriate investigations. In particular, you may want ask your physician to screen you for diabetes mellitus which is a common cause of excess thirst and urination.
One thing that pops into mind is diabetes. One symptom is excessive thirst. But a simple test can check for that. Or it could be a habit. My husband drinks a lot of water. I'm not convinced he needs that much because he also urinates very often due to the water intake. But it's become a habit with him. He can't go anywhere without a bottle of water. He actually gets a bit tense. It's best if you get checked first to rule out health issues.
It would be wise to ask your Doctor to run some blood tests. It could be many things from a psychological issue to the onset of diabetes.