I’m a believer in the less is more theory. When I started I was somewhat sporadic with my sessions, due to time/privacy issues. I would stretch when I could and do a jelq session here and there. I still found that I was getting decent gains. Now I have amped up the intensity a bit and try to be much more consistent with my sessions, and I notice that my gains have slowed but not stopped. There could be other factors at work, this is just my observation about a possible intensity/growth correlation.
As for the pain in your unit and the fact that it feels like a wet noodle, these are certainly what I would consider negative PI’s. If you haven’t already, you should read this thread on Physiologic Indicators:
Physiologic Indicators (PIs) to help growth!
Hope this helps. Take care of your unit, it’s the only one you have.