I'll try to make this short. I know most of you have busy lives and I'd prefer not to waste your time. This is what has helped me with my cystic acne more than anything else:

1. At night in the shower, wet face with water, pour tea tree oil into my hand, rub it on my face for 30 seconds. It should sting a little bit. Rinse it off, use regular cleanser (I use Simple moisturizing facial wash), rinse, let skin dry completely.
2. Apply Differin gel 0.1%.
3. Go to bed.

4. Wake up, use a moisturizer with SPF (I use Aveeno positively radiant daily moisturizer SPF 30).
5. Go on with your day.
6. Repeat from #1.

I don't do anything extreme like cutting out food groups, changing my pillowcases every day, or rubbing urine on my face (yeah, that's a thing).

I think the tea tree oil helps kill the bacteria, the facial cleanser is gentle, the differin gel improves skin cell turnover, and the SPF prevents sun damage.

note: I don't moisturize at night because my skin's oil production seemed to regulate when I stopped.

When first starting Differin, skin will get dry, so I recommend using it every other night for 2 weeks, then using it every night.  I've been using it for 2 months so far.

Though others have experienced an initial breakout with Differin, I haven't (at least nothing too different from my acne before). Last month, the cysts seemed to come to a head (strangely) and popped easily. If I did get new acne, they were tiny whiteheads that would heal quickly.

For a week now, I haven't had any new pimples. I don't get cysts anymore, thank god. The hyperpigmentation is fading. I feel good enough to stop wearing makeup. My dad said: "Whatever you're doing is working, your skin looks much better."

a bit of a before/after, 2 months progress: 

All that's left now is some redness.

I know you're probably already on some regimen, that's fine. But if that doesn't help I'd encourage you to try this.