The Bride of Habaek (2017)

This is the Korean version of the same story with more twist and plots. it has 16 episodes of 70 mins each starring Shin Se Kyung as Yoon So Ah (female lead) with
Nam Joo Hyuk as Ha Baek (River God).

the main lead is from a fantasy world.
he also has superpowers
the plot is interesting

The synopsis seems quite similar, struggling psychologist, god/emperor who believes that they are who they are.

A tale of love and adventure between an immortal fox and an artisan goddess. An eternal love that will face enemies in heaven and on earth.