Damage is the word. I had a situation a while back from putting too hard of a tug on. I have since been backing off on intensity because I really did do some nerve damage.
I have been really analyzing my grip and realized that when i grip too close to the head I am putting too much stretch and clamp where the head joins the shaft. This has caused some loss of sensation in my head. I also try to avoid putting too much blood pressure in the head when jelqing.
My new approach is to do stretching from a little lower than the head. I use less tension but consistent tension. My general routine is lighter too. Maybe I will gain slower, who knows.
Banana what kind of damage did you do?