Hi hete is your complete answer...... just know this problem is getting increased.decrease penile sensation mostly due to circulatory problem or nerve damage. Do you have history of spinal trauma? Spinal injury, penile trauma or circumcision can lead to nerve damage and decrease sensation. Decrease penis circulation may be due to heart problem like CHF, excessive weight, sedentory life style etc. Sometimes sensation lost because of thickened penile skin as in overmasturbation, dry and rough inner cloth. To regain sensation normal make life style healthy,reduce weight, avoid smoke, avoid alcohol.rule out diabetics also .take vitamins tablet if necessary