Help me, Please

I think you should give extenders a shot.

That septum may surrender under constant low tension

I guess the septum surrenders but the nerve overreacts. Actually is there difference between the two?

I don’t think it will work to be honest. I tried to follow a routine with silicone condom to keep it plump and extended but I had bad PI’slike now.
Now I measured and realized that I have no tunica gains at all,, ligs only.

never heard nerves are a problem to gains

a silicone sleeve has nothing to do with a extender

I know but I am pointing that keeping it extended for too long give me negative PI’s.

I think the main idea of the septum I to protect the dorsal nerve . My logic is - if the septum is relaxed the nerve is not protected and gets irritated.

But I have to idea why I am going back and forth all these months.

negative PI are not result of a single factor. You should not worry much about them when you are engaged in something totally safe like extenders
Your problem will be overcome with a lot hours a day in extender. PI can be negative , but then you will recover PI with a larger dick