Passing urine is becoming a problem. only if i drink excess water, i am able to discharge with decent flow. else it burns and discharge is slow.

Infection/stricture: You may have a urinary tract infection which can cause symptoms of burning with urination and a slower stream at times. However, you may also have a stricture of the urethra, where scar tissue narrows the channel. This can cause slowing of the stream, the need to strain to void and irritative symptoms. See a urologist for an evaluation.