Which local platform/model are you using? Would love to follow your project.
I built an AI journalling assistant plugin for Obsidian that has the option for 100% local and private use via Ollama and the model of your choice.
https://github.com/clairefro/obsidian-chat-cbt-plugin
Not a replacement for human interaction, but finding it actually really helpful for getting out of negative thinking spirals in between therapy sessions. Plus it has endless patience :P
I feel LLMs work well as objective sounding boards. Trying to build something similar to the OP for this reason!
Have you released your source anywhere? I was planning on putting together something similar but I'm always happy to find a giant whose shoulders I can stand on.
I would never use an external system for this. Even ignoring the privacy issues, and they are plentiful, it makes a lot more sense that you tailor the AI therapist to your needs, which most of the time are not generic needs. If you're in a therapy program you probably know those needs better than most people and can concretely ask the AI to assist you in meeting them over a longer period of time.
I'm happy with my system, it's a little clunky still but it is doing the job in assisting my recovery, which is all I want.