You could work part-time to help support project.
But you need a new opportunity to pay your bills etc.
That is the money need it to make the product valuable to users. Without it, the product provides 0 value to users. Let's say there are many companies in this space, all spend at least that amount of money to launch.
$0 of these millions is on marketing.
Since you are competing with existing companies, how are you different enough to be attractive to investors? The fact that you haven't been able to raise any investments to date suggests that those who passed on the opportunity could see things that you are ignoring.