Am urinating more than 4 times an hour. Am worried. After losing the fluid, I feel dehydrated, I drink more water and urinate even more. I can't sleep?

Check with doctor. Increased urination can be due to infection or diabetes, bladder or kidney or hormone problems, or just drinking too much fluids. It sounds like you are making large amounts of urine. Normal amount varies due to intake of fluid but is usually 1-3 qts/day. You should get checked with full medical history, exam and probably some blood and urine tests to determine what is cause and how to treat.
Polyuria. it is not normal to be passing urine so often and drinking more to keep up with your fluids. You should be checked and have your urine, blood sugar and electrolytes checked. Sometimes symptoms like this can form as part of a habit. All the best and feel better soon.