Guide me Sensei

The_Bishop

First off, I don’t think you should be too concerned with getting and maintaining an erection. Focusing on that aspect of usage can create its own impediments. It (an erection) simply is not necessary to experience the pleasure sensations being generated by your prostate.
Secondly, I’ve found that the pleasure waves are cyclic in nature for me, that is, they will often build and then fade and then build again only to fade again but then when it builds again it is usually a little stronger and lasts a little longer. This cycling can occur for well over an hour building to some pretty intense levels. One thing I have realized that can easily break the cycle however is to start thinking too much, trying to analyze the feelings seems to kill them, while just allowing myself to ride along with them, enjoying them, experiencing them with out analyzing them seems to allow them to continue indefinitely. So what do you need to do? I recommend just letting go of the analytical thought processes and respond on an emotional level to the physical sensations your body is sending you. I don’t think one can force these subtle feelings to occur, you just have to patiently wait for them to emerge from within you as you employ the breathing and contraction techniques that are effective for you.
This may be difficult for you as you have built a strong conditioned response using your massager as a masturbatory enhancement tool with focus on your penile sensations. I know this feels very good but it could be counterproductive to progress towards the Super-O experience. Perhaps reversing the frequency of sessions employing “hands-on” edging will accelerate your learning.