Help needed with skincare routine after acne flare-up

Hi everyone! I’ve been exploring Korean skincare since September 2024 to help with my acne scars. I’m 26 with combination/dry skin.

At first, I used a cleanser (not shown in the pictures) that dried out my skin, so I switched to my current routine and added the Cos De BAHA Tranexamic Acid Serum. It kept my skin hydrated, but I didn’t see much improvement in my scars.

In December, I tried the ILLIYOON Ceramide Ato Concentration Cream for winter hydration, but it caused painful pustular acne. I gave my skin a 2-week break to recover and then replaced the Cos De BAHA serum with The Ordinary Niacinamide 10% + Zinc 1%. Unfortunately, this triggered another acne flare-up (see pics 2 & 3). I stopped using the serum 3 days ago, and while the pus is mostly gone, the red pimples are still there.

Should I focus on hydration for now? Could Zinc be the culprit? I thought niacinamide was mild, so I’m unsure what went wrong. Any advice or product recommendations would be greatly appreciated!

Thanks in advance!