When I was about 16 my acne was so unbearable it was making me depressed, so I went to the doctors. After trying numerous antibiotics etc I began to think that nothing would work (I had already tried everything possible in the shops). It's not ideal for everyone and is only really for quite severe acne but I went on a pill called Dianette, it also acts as a contraceptive but is primarily for acne. It blocks a receptor which produces excess oil in your skin which gets infected and causes acne. It can have some pretty bad side effects but works incredibly well, my skin is now completely clear! You can only be on it for about 18 months but it can really help get through the bad acne and if it makes you feel bad you can just come straight off it
In short, you could go to your GP if nothing over the counter works for you and see what they think
