Have you tried any topicals? The medications you listed sound like they are all antibiotics. My experience taking antibiotics was that they all eventually stopped working because the bacteria builds up a resistance to them.
Maybe you can try a cleanser with benzoyl peroxide (proactiv, carley's clear&smooth, oxy wash, etc) or try a topical cream (differin, retin-A, etc).
Luckily there are many things you can try before going the accutane route...
Good luck!