Bloating can be cause by a number of different things; hormones, food intolerances/allergies, food intolerances such as lactose intolerance, certain foods such as cabbage and brocolli; medical conditions such as tumors, etc. I recommend that you make an appointment to see your doctor.
When you're bloated do you also feel gassy? Simethicone might help. It's OTC in the same area as other digestive aids. Carbonated beverages help my body release the gas. However, carbonated beverages cause some to feel bloated. If you use a straw to drink you may be ingesting too much air. Chewing gum can do that too.
I don't think it's a water issue. Tea is a liquid and will keep you hydrated. Even if you didn't drink enough fluids you wouldn't get bloated. You could become dehydrated.
Lactose intolerance is a common cause of gas and bloating. I'd start by eliminating all dairy products and see if that helps. My grandfather and father were dairy men. Turned out my father and I are both lactose intolerant. What a bummer! :):)
If trying some simple measures doesn't help, see your doctor.