Joe is right. Warm it up and it might finish.

Relying on wild or native yeasts can be a bit of a crapshoot. You may
end up with a strain that's ideal for wine and can ferment it to
dryness, but you could just as easily end up with a strain that either
doesn't finish, or produces off flavors or aromas. In the future you
may want to consider inoculating with a cultured yeast strain.

Greg G.