There is quite a bit of advice in this thread, some by people who've been in your shoes and some who haven't. So be careful about the advice you follow, it's ea

There is quite a bit of advice in this thread, some by people who've been in your shoes and some who haven't. So be careful about the advice you follow, it's easy to make a bad decision at this point in a startup. My advice. Go (back) to consultant mode. It failed. You know this, it's in the OP. Don't give back the cash, they invested in your ability to grow something. Show them they didn't make a mistake. Work on something totally new and don't feel constrained to do something anything even remotely close to the old idea. Don't start building another software monstrosity. Find a real problem and a way to solve it. You have a year of runaway to sell something that can grow into something real. That's not too bad.