I had awful, painful cystic acne all over my face, mostly my chin, mouth and jawline, like you, and I was put on Minocycline and I immediately saw drastic results within three weeks. By the third month, I was almost clear save for a couple little pimples (which i really didn't mind , i'd rather have tiny bumps rather than having quarter sized cysts). She then told me to continue on the antibiotic and added the birth control Alesse to see if the rest of the remaining acne would go away.
Today, I must say that my face has never been this clear since a year and half ago! I'm only on my first month on birth control, so I'm not sure of its true impact yet, and I'm still on minocycline, and I still have two months or so worth of prescription left. The true test is whether I can remain clear even without the antibio. :/
I still have post-inflammatory hyperpigmentation but that'll go away with time.