Can you make an amicable exit with some rights to the code? Seeing as you haven't been properly paid the copyrights or even the non-exclusive rights to it coul

Can you make an amicable exit with some rights to the code? Seeing as you haven't been properly paid the copyrights or even the non-exclusive rights to it could be a fair exit and you say that you are proud of the technical solution. It's only relly worth it if you can see a business in it though or can pivot the work you have done. It sounds like you have had an expensive lesson in picking partners, try to exit as cheaply as possible where the costs factored in include family relationships as well as your time. Others may also see the end but not want to be the one to call it but it is worth having a story for what you will do instead. As others say forget about the sunk costs just optimise for the current situation and the future.