Why oh why has your doctor not referred you to a skin specialist? You really need to insist on this next time you go to your GP. Do the spots appear worse after eating certain foods? Things like dairy and sugar are really not good for your skin (I'm a fellow sufferer too), and you need to be drinking loads of water too, continuously. Zinc supplements are supposed to help, as is obviously cleaning you face as often as possible.
Not sure if you're male/female but this could be hormonal, in which case needs to be treated - you might have too much testosterone (even if you're female).
Go back to your GP and demand to see a skin specialist. Roaccutane is not the safest drug, and doesn't get to the bottom of what's causing this.
Good luck x