Please recommend a good treatment for skin pigmentation!

I've been really worried about my skin pigmentation lately. ㅜㅜ Every time I look in the mirror, I get stressed out because of the dull spots and uneven skin tone that are noticeable due to skin pigmentation. It's even more of a headache because once you have freckles, dark spots, and acne scars, they don't go away easily. ㅜㅜ
I'm looking into everything from functional cosmetics to dermatological procedures to address skin pigmentation, but I'm having trouble finding information. Could you recommend a treatment for skin pigmentation?