I had a similar problem and finally went to a urologist. My prostrate was fine, but I had a urethra stricture. For whatever reason, the tube that urine flows down had a place that was almost closed off. I had surgery to open that up and have to go back every 3-4 months to get dialated because of scarring. The only way to know if that is the problem is go to a urologist. He can run a scope up inside to take a look at things. Good luck.