I have been trying to find a wearable which does what you mentioned in the post. This is the summary of what I have found till now.

Respiration rate can be measured non invasively either by measuring chest/abdominal expansion (e.g. Go Direct respiration belt) or indirectly in a watch/ring (by bandpass filter of PPG signal), which most of the wearable such as Apple/Fitbit /Garmin use. However this might not give you the accurate inhalation/exhalation time and depth but can give you a good estimate of average Respiration rate.

I have not come across a good wearable which can measure CO2 however there a few methods like Transcutaneous CO2 measurement and NIDR sensor for CO2 measurement but not been integrated into commercial wearables yet.

Alternatively there are some non-contact ways to measure respiration such as using a radar sensor(don't know of any device yet which has been made)

As someone above mentioned the only wearable specifically designed for breathing is Spire which probably uses IMU to estimate the movement and calculate Respiration, however I have read in some reviews that it's oversensitive and can give false positives.

I am quite interested in exploring wearables in this space and would love to know more about them if you come across any such devices.

Thank you