What hurts me the most about this investment is the time and energy I put

THIS.

The association of intangible investment (time and energy) along with the money....

Only compounds the pain.

I lost $50k and more on a "data error" that wasn't handled well. And then the founder decided to say goodbye. Hurts every day as I think about it (because I also invested time and energy).

Treating it as expensive learning life throws at us.