My skin condition isn't recovering like it used to..ㅜ

Maybe it's because I haven't been getting enough sleep lately, but my complexion looks so dull. In the past, even a good night's sleep would instantly brighten my complexion, but now, even with a generous amount of makeup, my skin looks dull.

I'm definitely in my 30s, so maybe basic care alone has its limits... Yesterday, I looked in the mirror for the first time in a while and I felt bad because I saw dark spots under my eyes, so I bought a new vitamin ampoule.

If I apply it consistently, it'll get better, right? Does anyone have any special skincare routines they pay attention to when they're not feeling well? Besides vitamins, is there anything else I should be taking or applying?