Hi I have infected with some kind of infection on my penis under foreskin it look like white pimple.this happen few days ago suddenly.can help me to know the reason... is that something serious.

What measure should I have taken to overcome with this problem.. should I control on sex with my partner.

Kindly advise.

Get checked out by a doctor on this one. You also need your partner checked out if it turns out to be an STD as you could just keep reinfecting each other.