Have been using Apple Watch for months now still doesn’t track wrist temperature why?

Wrist temperature is a feature of Apple Watch 8 or Ultra. Your profile noted below your post seems to show you have Watch SE which doesn’t support temperature measurement.

Is your tag line correct in that you own Apple Watch SE? If you do, the reason its not tracking temperature, is Apple Watch SE is Apple's least expensive watch and temperature tracking is not a feature available on SE models. It simply doesn't have the sensors to track temperature. From the Related Article link at the top of this page, it clearly notes to track your nightly temperature, you need an Apple Watch Series 8 or Apple Watch Ultra.