Ahh yes, I know a few people who work in healthcare tech in Germany and it seems like you're way ahead of us. I'm glad you're able to leverage tech a bit more effectively over there. My impression is that the tools the US uses are far behind due to over regulation, which I hope is changing as a result of covid.
And don't be sorry! Most people who have a successful startup have many failed startups behind them, there's only one way to learn most of these lessons.
My PT uses a software exactly like this, and that made it possible that my progress was tracked during my months long vacation too, all online.
The app: https://medbase.physiapp.com/ (in German)
PS. it worked, my back problems are gone.