You should take a break, it's normal to go through down periods. Work coding is also generally dissatisfactory compared to personal fun coding.

Personally I have found that the sky is now the limit thanks to AI assistants! I was never the best coder out there, probably a median level programmer, but now I can code anything I imagine and it's tons of fun.

Find some creative projects you want to work on and code them up!

One modification I would suggest is to add a bit more to the initial prompt like:

"write as if you are a person from {{REGION}}. Modify your language to proficiency level {{PROFICIENCY_LEVEL}}"

that way I could for example, speak as if it's someone using Mexican Spanish vs Madrid Spanish vs Chilean Spanish, etc.

Secondly, you could include the user's speech transcribed as part of the conversation window

Amazing idea, do you think this should be a freeform text field the user can enter to add their own prompts to or should it be a checkbox/select on the homepage so the user can pick from a limited set?

I think a drop down when you first choose the language, and it can be optional. You can test it with a few languages at first, to see how it is.

Just tried this for Spanish and it works incredibly well. I have been hacking on something similar for translation (it's really quite easy too, just a few prompts), but I was using Google Translate's interface for vocalizing! This is seriously good stuff, really nice work putting it together.

I will probably use something like this for language practice.