I had the luxury of friends/roommates, where we used our purchases on one card if someone was in your situation and pay them our share. We just dont look on our cashback things for that month and help the other person.
But it wont work for everyone (even myself now). I used to pay the auto insurance for full, but you dont have that luck.
other options: prepay utilities, buy grocery -non perishable (like paper towels/liquids, target often has deals) or store card, Amazon, ebay gift card (i would suggest to buy some on small $, if incase you are going to gift someone) or even buy gold online and sell it (you can do online without ever getting a physical-only if you need larger amount)