How to recover normal penile senstivity which was lost due to masturbation to make sex/masturbation more pleasurable?

Take a break: If you give your body a chance, it will likely heal itself. This means avoiding stimulation of the penis for a period of time. The nerve endings in penis will likely recover their normal amount of sensation with some rest. If they do not, it would be time to see a doctor.

Therapy: Try to find a qualified sex therapist. This can be a difficult problem but you are young so you should do well if you address the problem now. Try to avoid masturbation and pornography as much as possible. The more you masturbate the worse this problem will be.