This is going to sound like I'm berating but you need to think about why your partner has not been working since August.

I mean more that it feels like this was a situation where she lost her job and you guys just kind of tacitly agreed that you could get by for a while. So she took some time for herself. I'm not here to judge about that particularly, but I am here to say that this is why you need to have a budget and a plan because the day she lost the job you could have said "you not working is going to put us xyz behind." and if that isn't motivation then you have bigger problems. The most alarming thing of this entire post is that your partner didn't even think to get a seasonal job at like Target.

This forum is riddled with posts from people who are in desperate straits because their partners are terrible with money and don't understand consequences. It is natural to want to indulge our partners so easy to ignore little things here or there. It is also natural to want to indulge ourselves once in a while and maybe also keep that from our partners. Then you have an emergency and the little things add up really fast, as you have seen.

That said, your situation is far less dire than you are thinking, if she can go back to work. I mean this to encourage you. I know financial stress really sucks.

The logistics of the advice in the other comments is good.