lack of penis sensitivity

You could try laying of the masturbating for a while,
If you masturbate regularly,try and hold off and your
sexual desires will be more focused on your wife and
you may cum more quickly.
Your size in not the problem, you are in the average range even on the high side for a Asian man.

thank you nww. another thing is I cant feel much if touching penis head softly.. is there any way to restore it?

Again I think you should lay of the masturbation for
a while if you want to cum quicker with your wife.
The other question is sensation increase you are
looking for and mention restore which makes me believe
you are circumcised despite most Asian men being uncut.
If indeed you are circumcised you will just have to live
with what you have and try and develop the best technique
in way of touch, position and maybe increased lubes to help
with your stimulation.
If you are uncut it seems strange you have a low sensation,
again if uncut do you have any issues with the foreskin being tight.

yes I was circumcised as a teen but this problem starts 2 years back. I think its not the coz as previously I had strong sensation. I used to hold the head tight while masturbating. now I am trying to lay it of which is difficult.

Snik.

Ok I think I see the issue.

Most circumcised guys seem to squeeze the head like they are trying
to extract sensation from the head/glands, basically trying to make
a false foreskin to rub over the glans.
I think the problem is you have been masturbating for so long this
way with pressure and now with your wife when your having sex with her
you are not getting the pressure like you do when you use your hand.

Again lay of the masturbation if that's possibly and see if you can
get some sensation back by your penis not being so used to having pressure
placed on it. The other issue with cut guys is the glands
are exposed to all kinds of rubbing with cloths and this also desensitises
the area, if you don't already it may help to wear cotton boxer shorts so the
head is not always rubbing up against underwear.

Have always wondered if cut guys could also use some kind of moisturiser
to help moisten the area, if you check out an uncut guy when they roll
the foreskin back it look's very moist and pink but you would have to
research what kind of moisturiser you could use, I would be very careful
in your selection.

thanks again nww. I hope it may help me..