Yep, sounds familiar. I had the same thing happen when I was younger. Probably just the rush of T that's causing it. Really, all I can say to help is that it went away once I started transitioning, especially after I started HRT. Then orgasms just confirmed my desire to transition as they started to...feminize, I guess is the best way to say it. Whole-body sensations, waves of pleasure, not like the "burst and done" that I used to have.