Which procedure would help correct my eyebrow asymmetry?

I recommend you botox treatment. However it is a temporary solution. If you would rather something permanent you can get a browlift. There are some types of browlift which will be very suitable for your case.

The easiest solution to balance your brows is to use botox to weaken the muscles that are responsible for lowering your brows. By weakening these specific muscles, it will allow the muscles responsible for lifting your brows to be more dominant.