Well, the peeing sensation could mean you're about to cum, so you might wanna roll with that and see where it goes. Also, how long are you expecting things to last? I can orgasm for extended periods, but that's been sort of trained, not something that just happened. I think most people have quick sensations like your describing, at least that's what I remember from when I was younger.
The best thing you can do is experiment. What works for one won't work for another. Try different vibrations internally and externally. Try different shapes and amounts of pressure. When something feels good, keep doing it.