14 days after my CO2 fractional laser, my skin has become darker instead of getting better.

You may be having post inflammatory hyperpigmentation. You should call your doctor for a in-person evaluation.

Post inflammatory hyperpigmentation (PIH) is a common cause of increased pigmentation after CO2 laser resurfacing. This usually occurs around week 3 and can persist for 6 months. The good news is that PIH always fades over time and it can be treated with topical bleaching creams and exfoliators to assist with the process. Follow up with your dermatologist to discuss these issues.

Hello,You have PIH (post-inflammatory hyperpigmentation).  You appear to have been a poor candidate for fractional CO2 laser.  Fractional CO2 is good at removing age spots, it is usually not a good choice for other types of pigment like hormonally induced pigment or melasma.  Most types of pigment that are not directly age or sun related are made worse by inflammation and CO2 laser is very inflammatory (as are other types of invasive lasers and chemicals).  You will probably be able to get rid of this PIH with a combination of hydroquinone and steroid cream, but it will take some time.  Non-invasive treatments like IPL may also help.  Skin that reacts like yours needs to be "babied" with gentle treatments and aggressive avoidance of sun.  You need to understand that if you can't get rid of all the pigment using gentle techniques, then you need to accept it.  The temptation to be more aggressive is likely to backfire.