Most of the rich investors i know today, didn't give up when they encountered a challenge. What they normally do is go back to the drawing board, check why they failed and then launch back for a more successful journey using a different strategy.
You need to get back to your own drawing board and check where you got it wrong in terms of forcasting before investing. Project utility, core team and team of advisers, competetive advantages amongst other things are what you need to check in your analysis of a project. Dont give up bro, the future will always be brighter if we get it right.