Advice before tomorrow night's session

So tomorrow will be my 13th or so session. I am feeling very comfortable with it in, and my process usually goes like this:1. Insert aneros helix syn.
2. 5-10 mins of deep breathing and relaxation with no contractions
3. Start light contraction, hold for 2-3 mins
4. Notice nice feeling in my prostate, sort of a tickle, or itch that I am getting closer and closer to scratching
5. Slightly increase my contraction, hold some more, pleasure increases.
6. Feeling a strong tickle at this moment, I believe this is my prostate. at this moment, feel like I should take it up a notch
7. Hold a very hard contraction, for ~3 mins, Pleasure increases at first, but then fades.
8. Can never get back to that point for the rest of the session.

So you may see my problem. I start with light contractions and get results. As the pleasure increases there becomes a point where, maybe I get impatient, and think that contracting harder will increase the pleasure. It's almost as if I then contract so hard that i kind of knock the wind out of my prostate. It doesn't seem as sensitive anymore.

I'm thinking tomorrow night I will stop at step 6 and just hold that level of contraction for a while. But how long should I hold it for? Should I go for the long haul and hold for like 20-30 mins? It's a pretty light contraction so I probably could hold for that long if I wanted to. Are harder contractions directly associated with more pleasure? Is this something that maybe comes with time and practice? Would love some advice.