Does your resort rent just boots, some do. Then it will only cost you a few extra bucks and still be able to use the rest of your gear.
I don't think there is a "home remedy" for poor fitting boots, you also mentioned the liners don't match as I addressed before. I truly think you need to re-visit CL for a better pair of boots, borrow a buddies spare set, rent some or buy a new pair.
Discomfort like this takes all the fun away as you already know !!!!
-I'm Slyder and I suffer from "Gummer Syndrome"