I had problems with being pee shy for years. It used to really piss me off (pun intended)! If I walked into an empty mens room, it was never a problem to use a urinal. Once I started to pee, I was fine. The Pope or Queen of England could walk in on me and I'd be able to keep peeing with no issue. Conversely, if there was any other guy in the mens room when I waked in, I'd sometimes get stage fright at the urinal and couldn't release the flow. Then I'd get frustrated and embarrassed if anyone saw me standing there not pissing. My MO was that if I saw another man in the mens room, I'd duck into a stall. I had no problem peeing with my friends outdoors in the woods or in the desert, but couldn't pee next to them at a urinal. Instead, I felt like a coward and used the stall.
It bothered me that I had an issue using urinals when others were in the room and really wanted to get over it. I researched "pee shyness" and found that it's caused from anxiety. Ultimately, we need to relax at the urinal and let nature take over. Behavior modification works, but it requires time and patience. You can't relax if you're worrying about what if I can't start to pee or what if other guys in the mens room might look at me, etc. What worked for me is to look straight ahead and zone out on the wall. Look at the grout between the tile in front of you. Mentally block out any activity around you. Doing math is good. Thinking of the lyrics to your favorite song works also. If you can tune everything else out momentarily, the flow will start. Once the flow starts, you're fine.
I worked my way up. If the urinals had dividers, it was fairly easy to look straight ahead and release. After a few weeks, no problem. There were some places that the urinals didn't have dividers and I was fairly exposed. I started by using the urinal the farthest from the door where there was no one on the one side of me. As I began to have success every time starting the flow, I'd try using another urinal in the middle where there could be guys on either side of me. It seemed as though my plan was working. One time I walked into a mens room at Happy Hour. There was just one urinal right next to the sink with no divider. There was a guy at the sink. Would I be able to release the stream? I just looked straight ahead, and voila. There I was pissing at an open urinal with a guy less than 2 feet away from me. My plan to look straight ahead until the flow starts worked. Ever since that night at Happy Hour, I've been able to pee any time that I've needed to without hesitation. It's great to be free of the restriction and to pee when we need to.
Best of luck to those of you that are working on to overcome pee shyness.