Too sensitive penis, cannot cum

Hi ,

My penis head is way too sensitive to the point of painful when receiving hj and bj. Its erect but after 45 mins or more still cannot cum because i feel the displeasure from the sensitive head. Its weird because most of the people I heard cum very fast because of sensitivity, but mine is the direct opposite.Only when i masturbate with foreskin covering then can cum.

Anyone can offer some advice?