Acne won't go away!

I've had acne now for about 4 years. I recently graduated high school and am about to start college. I had acne throughout high school and always treated it. Originally I was put on oral medication that I took twice daily and given a cream called Differin. That went on for about a year or so and didn't work. I was then put on other oral medication and switched to a different cream. Long story short, I've tried every cream, benzoyl peroxide, Differin, Retin A (which I'm currently on), etc. etc. A year ago I was put on Accutane and that worked alright. I was taken off of it in January of this past year and put on oral medication and benzoyl peroxide. Now I'm not taking anything orally and am just using the Retin A cream at night. I wash my face well, don't scrub to hard, get exercise, and do everything I can to treat my skin good and I still have bad acne and still have red blemishes from old acne. What's next? I'm 18 and I can't get rid of acne, it's really annoying.