I hear that mandelic acid is really great for hyperpigmentation! I use 8% mandelic acid serum by Vivant skincare and it makes my hyperpigmentation look much better after as little as week, as recommended by my aesthetician. I saw my derm today and asked her about it and she said she's had many patients who say they love mandelic acid for their acne/hyperpigmentation as well. Best of luck!

Lemon Juice (applied topically)

do some research on it.

Sorry, but lemon juice is way too acidic for your skin! Your skin likes to be in a pH of 5-6 (so ideally 5.5), and lemon juice is about a pH of 2.

This can damage your skin barrier, which can cause it to perform below its full potential at regenerating its skin cells (and thus reducing the inflammation of active pimples). 

My best recommendation is to use a good quality Vitamin C serum. They're super nourishing for your skin and is effective at fighting acne and fading dark spots. Read more here: http://[link removed]

I think it's going great for you. If your skin responds well to the treatment that you're currently using, I think you should already stick to it and don't experiment with something else.