Mr. E: Your penis shouldn't be de-sensitizing due to the exercises. In fact, many men report that they feel even
more sensitive after they start to PE.
I'm not sure what the problem could be. Are you jelqing your glans or griping them in some way? This is a big no-no. Also, how much intensity are you using to jelq? It should be a light, graceful grip.
I'm curious,
what are your PIs like? You shouldn't be overtraining with only 40 jelqs, but you never know.