I would suggest Accutane, you need a prescription from your dermatologist though. Beg your mom to take you. It really works but its a very strong med, and very expensive too (like $1300 for 6 months-insurance will cover it)...but it works miracles. You would also need to take monthly pregnancy tests (to ensure you're not pregnant because it can severely deform the baby)
I had bad acne for years as a young adult and this really worked for me. I was also on many topical prescriptions and tetracyclene (another med from the derm) before Accutane but Accutane is what really helped me. Now my skin is as clear as a models, really and I also get compliments all the time about my nice skin. I also use Pro-active for maintenance. That works too but it has benzoyl peroxide in it. Hang in there. Your skin will clear up, you are still very young and it WILL get better! Just have patience!
Best of luck!