Wow, what the heck just happened?

I just had the strangest experience and something i never imagined i would encounter using the Aneros. I purchased a progasm for Christmas thinking i might be able to achieve an anal orgasm one day if i practiced enough, so i used it a couple of times and had pleasant experiences each time, nothing beyond that. Tonight i thought i would try again, so i waited until night and totally relaxed before i inserted the progasm. I slowly squeezed and relaxed my pc muscle in various positions for over an hour until i ended up laid on my back with my legs open and knees in the air. I began squeezing my pc muscle and breathing out at the same time until my mind wondered and i started doing it without thinking, this is where the strangeness started to happen. I can only guess that i entered into some kind of meditative state, as its like my inner vision started to go cloudy and i started to feel a damp pleasure start to spread from what i can only guess to be my prostate, it was like my consciousness shifted to a more dreamlike place and i almost started to dream/hallucinate shapes and colours.
I think that i may have been building to a super-o, but it just managed to slip away from me and i returned back to my normal (yet more relaxed) state. The strange thing is that i felt the relaxed calm/rush that you experience after an orgasm, so i believe that my brain actually released the orgasm chemicals, but i didn't actually have one or experience the pleasure.
Has something similar happened to anyone else here? I certainly didn't expect to experience something like this, thats for sure! I'm amazed.