What is a good way on getting rid of acne?

I started washing my face three months ago, using warm water (to open and clean out my pores) and cold wat after to close them, it worked up until now and now it worse than ever all over my forehead and sides of my face.
What is a really good way on getting rid of acne with out buying a skin care product
(my face is highly sensitive to make-up, and skin care products)