Help me understand what is happening?

Still a beginner here, have a question but please bear with me laying down some facts first that I feel are contributing factors.

Usually I would insert my helix syn trident for my sessions with a condom and some lube. Sometimes I would need to do some contractions for awhile, while other times, I can just let the toy slide on its own and create some tingling in my prostate. I would keep playing and exploring the sensations but at some point I would start to feel a tingle. That tingle would lead into what feels like the calm before the storm where I feel nothing for 2-3 seconds before it rapidly increase in intensity quickly with 2-3 waves of pleasure and then followed by the overwhelming urge to ejaculate.

As I am way too fucking turned on when it happens, it would lead into a raging boner that would eventually kill any kind of build up that was happening before. I feel the erection actually misdirected or redirected my attention from my prostate to my rod.

At this point, it feels like I have switched train tracks, where before I was getting high on prostate pleasure and now I am 110% erect but am at the base 0% of what feels like the start of a cliche masturbation session. I would try to attempt to go back to exploring my prostate sensations but would ultimately become impossible as I would somehow, mysteriously lose my ability to get horny afterwards.