This is probably due to hormonal imbalance. There isn't much more you can do to speed the process up, but you can probably work more on skin care, which usually does help. Remember that acne is an infection and it's easier to keep your skin clear than it is to get it clear. One of the keys is keeping the skin clear of bacteria. Shower 2x day, using dial antibacterial bar soap. Make sure to wear fresh shirts to the gym every day. Change your pillow case just about every day and change your sheets 3 times a wk. Keeping the baceria away will make a difference.
If this doesn't help, going to the Dr to get the right antibiotic can help, if you know when you are going to break out. The step after that is accutane, which is harsh but will CURE acne when used correctly