Hi Vishika ,
Thanks for writing in.
is caused by hormonal
Blockage of sebaceous glands causes papules and pustules.White substance is secretion of sebaceous glands.
Acne problem is related to menstrual cycle
Acne is treatable now.With correct treatment all your pimples ,
and dark spots can be treated.
To start with you have to apply Brevoxyl cream twice daily .
Also you can use anti acne face wash like Brevoxyl face wash.
Avoid any hair oil to hairs.Avoid any other moisturizers or cosmetics.
Use good quality sunscreen like SUNCOTE gel daily while going out.
Please visit qualified dermatologist
for giving you specific advise.