Go to a pharmacist and ask for Dalacyn
Or anything with the ingredient called Clindamycin
its an antibiotic that i use and the effect can be seen within 1 weeks.
It really helps...and it only costs like 30 bucks

Also if you want to prevent acne do change your lifestyle.
Sleep early
Eat healthy( more greens)
Exercise
improve personal hygiene. (change your pillow case often)

I know you hear this very often but trust me if you do all the above it will heal your acne faster than any medication on earth and it will prevent your acne from coming back.

If your really desperate....try being a vegetarian for 3 days straight and u will see the result on the 4th day.

As the saying goes..."what you eat is what you are"