I didn't have an issue when I was young, but I've had passive dysphoria ever since I started having sex at eighteen. I had a feeling of wrongness and a sort of penis envy, but the dysphoria was rather vague, more like wishful thinking at first. Then, I got a steady boyfriend and started having serious problems with penetration down there. At a certain point, I just switched off the feelings. Well, mostly. I still wanted a penis, and I still experimented with packing at home (socks, my boyfriend's wallet, whatever).
I didn't start having really active dysphoria until I started my transition, and even then, the feeling took time to build. Now it's full-blown and keeps on building. I have dysphoria about having a hole and not having a typical penis. I am dysphoric about the innards I have. I have dysphoria about not having testicles. I am dysphoric about peeing sitting down, but I haven't found an STP solution that works for me (I gave up pretty quickly). I have dysphoria about not having a prostate, for Pete's sake. The bad feelings tend to snowball, so I go through cycles. In addition, I have a strong sex drive now, so I indulge it. The more anxious I am, the more I masturbate. The more I jack off, the more depressed I get with the status of my parts. Eventually, I bottom out, bootstrap myself, and start over again.
The only thing that really helps me is packing, and it doesn't help as much as it used to.