Having acne, wwe at your age is a very common problem and understandably embarrassing. I would recommend a visit to your Dr who is very used to seeing this sort of problem and will offer you some advice and reassurance. Certain drugs can cause or worsen the problem and so reviewing your medication will be worthwhile.
If you’re interested the cause is not entirely known but there is some debate over the sebaceous glands' overreaction to a surge in certain pubescent hormones or indeed certain bacteria may be to blame.
As to the effectiveness of clearosil. I'm not sure.... but its cheap enough to try..