Help! I am a 28 year old male who has no sensitivity in my penis.

The outer foreskin layer contains sensitivity nerve endings which respond to gentle touching during the early stages of sexual arousal. The sensitivity nerves of the inner and outer foreskin contribute to the experience of penile stimulation, up to and including orgasm. A "short foreskin" may be an indication of a deformity problem that is affecting the nerves endings.
I think your theory is right, since the short foreskin exposes the penis head, the skin has dried out (which is normally covered by the foreskin), and this could possibly have affected the nerve endings in the skin. Try some mild over the counter lubricant from the pharmacy on the head of your penis and see if that helps. Getting and keeping moisture to the penis head skin is important.

At your age many boys are multiorgasmic and that's what you are. This is quite normal. Even I had a real problem with erection not so long ago. It was terrible. My dick failed after several minutes! So after thinking about it and searching on the Internet I came across shoppillrx, website that had the Viagra pills to do everything. In fact I can last for hours and hours in bed, my whole life has changed now and I'm not shy about getting intimate anymore.