I have trouble peeing, and Im only 15?

I have trouble peeing, and I think I may have found the reason why. When I started masturbating, I didnt know what the heck was happenning, so I stopped my semen from coming out the tip of my penis and held it in. I covered the tip of my penis and when I stopped ejaculating, I let my semen out. I asked a question yesterday, and all three answers said it was bad. It is not an infection of anything, since this has gone for some time already, and I have had no infection-like pain. But I wanna know, could this have done some permanent damage or something and how does it affect me? I will see the urologist but the appointment is in like 2 weeks, and I just want to know that.