It is not rational to quit, seems more of an emotional decision which you aim to rationalize (justify). A rational decision: pay a tiny portion of your 200k to

It is not rational to quit, seems more of an emotional decision which you aim to rationalize (justify). A rational decision: pay a tiny portion of your 200k to someone else to build the prototype. Do the same to try to sell it. There should be a ton of programmers out there just as good as you are that can deliver a good product. Meanwhile, running this on-the-side-startup might take some of the emotional pressure off, give you fresh air and motivation. I am talking from experience, now I have two companies: the consultancy work (which mostly I dislike but pays the bills) and the startup that takes a little of my time to steer, it's fully staffed, self-funded and it's walking into its 3rd year of profits (which are now enough to pay half the bills). Think rational and controlled transition, not jumping into the void. Also, I did get to program some of the code on the startup so it was fun and distracting!