I have a problem: Why is it hard for me to urinate in a public restroom, specifically in a urinal, when there are other people in the room even though they are not beside me? When there are no people, I can easily urinate but when there are people, even though I can feel that it has to go out, it won't come out. How can I fix this? I need help badly.
The problem is you are getting tense because others might see, but in order to urinate you have to relax the muscles closing off the bladder. Getting individual muscle control, where some are tense and others are relaxed is difficult, especially in teens. The only answer to this is to relax. Focus on something completely unrelated to what you are doing at the moment.
To gain better conscious control, when you urinate, think about relaxing the muscles so that you get a heavier (not faster) stream. Over time that will give you some idea of what muscles need to relax.