I, too, had this issue for many, many years. I never did when I was a kid, but it developed later in my life. I could think of a few different reasons as to why this started, and what trauma may have caused it.
It was honestly DEBILITATING. Especially being in certain situations where you have no access to a private stall. I remember once having to pee so badly but being on a road trip with friends, getting out, and couldn't pee even though I had to pee SO BADLY, but couldn't because I felt like all my friends in the car were watching/waiting for me. I couldn't go, and didn't want to embarrass myself so I got back in the car and horribly struggled until we made another stop (with an actual bathroom).
Having since come to Zevism and the ToZ, this problem has almost entirely been eliminated. Now, I only seem to experience a problem if I go into a washroom and use a urinal where there is already someone at one right beside me, with no divider between urinals. Once they leave, I have no problem. Prior to this, I could not even use a urinal if a single person was in the bathroom - even if they were in a stall and I was at a urinal.
I am on the right track now to eliminating this entirely.
1. Do a Freeing of the Soul working. Do not skip for 40 days. You may have to do this more than once in order for the effect to take place
2. If you have someone really close to you, like a lover or maybe even a best friend, so not be afraid to hide this and speak about it - it GREATLY helps. We all have hangups on our soul and most people you are close with will be understanding and wanting to help. Ask this person to help you. If you are comfortable enough with this person, have them stand by you while you pee.
3. Practice peeing in public. Go to that public washroom, find a stall if you have to, or better yet, a urinal when no one else is around, and start peeing - while you are peeing (since you've already begun relieving yourself), picture and imagine other people coming in/entering the washroom, but that you are still able to pee. I practiced this every time, and eventually I was able to get to the point where it wouldn't bother me as much should other people come in
4. What really helped me was to go on a trip. I went to India where I knew I'd be placed in situations where private stalls don't exist and you'd have to pee around other people. I had several situations where I'd have held in my pee so much that I had to go SO badly, and forced to do it around other people. Eventually, it didn't matter if there were people around me - if I had to go, I would GO!
5. I know it's not healthy to hold your pee in, but I knew drastic times call for drastic measures. I found it helped to intentionally hold my pee in till I REALLY had to go (again, if you can, find a place like a public washroom where you know it's all strangers - no friends or co-workers to stress about), and stand there for as long as you need. Stand at that urinal as long as you need - close your eyes and picture yourself having that feeling you get when you've released your bladder muscle, that instant before you actually begin to pee. Even in normal situations, focus on that feeling and remember it. Think of that feeling in tough times and it will help
6. Fear is what needs to be overcome. This is so important. All my other points are useless if you don't actually take a step towards TRYING to overcome this fear. It's like that fear of wanting to ask a girl out, or even initiate conversation with someone you like. You won't achieve anything if you don't face your fears
7. Spend your free time DAILY stating positive affirmations. This is ESSENTIAL. Do this in addition to the Freeing of the Soul ritual. "In a healthy and positive way for me, I am now totally, completely, and permanently free to pee where I want, when I want, and around anyone I want. Any and all obstacles keeping me from peeing freely in any situation are now totally, completely, and permanent destroyed." Or use something to that effect if you feel another affirmation would be more useful or feel more comfortable to you.
All the best in your journey. As a Zevist you have the power to free yourself of any hangups, if you so choose to actually put in the effort and work on them.
I have Zeus and the Gods to thank for bringing me to this information to help myself where doctors, psychiatrists and therapists would have very likely been useless. We now have the power to heal ourselves. Use it, and you will thrive.
HAIL ZEUS!