Great post, but I can't help but notice:

My co-founder was able to sell far faster than I could build Customers became disillusioned I collapsed

Which comes across in the albeit very brief description as the root of your problem, it sounds like you didn't actually follow that "standard advice".

That reads like you started scaling before the product was actually viable, which is borne out by your first point of what you've learnt.

I also think I disagree with point 3 of your conclusions, if your partner had been raising funds instead of selling you could have employed more people to get the product ready. Easily said with hindsight I guess.