Honestly I don't think there's much to interpret.
My opinion is that you either need to abandon the upcoming demo day goal - or if you feel that you absolutely must be ready for demo day (eg the project is dead for some reason if you don't), find someone to fill in extremely soon that you already have a high degree of trust and knowledge of (you know that you can get along with them, and you know their skillset). That person doesn't necessarily have to become a long-term part of the company, however the accelerator won't be thrilled by a short-term patch either, because it'll imply disruption in the near future anyway. You'll also reasonbly need to give the contributor a small amount of equity. Maybe you get lucky down that route and find a long-term new co-founder.
If you don't already know some people you can potentially talk to about filling in for that role asap, then push off the demo day goal and take aim of a new goal. The sooner these decisions can be made, the better. See if your accelerator will bump you to their next demo day, if possible. If you need a co-founder for the next demo day, then immediately begin looking for one.
My personal opinion would be to abandon the upcoming demo day and shift your horizon, unless everything is going to die if you don't make that. If you're confident your product is truly worth doing (take a bit of time here and now and confirm that for yourself), then it's still worth getting it ready for three or six months from now, instead of a month from now.