[dra&pigs]

I don't know you, and I am not going to judge you without full knowledge of your situation, but you should try to get him to a vet ASAP. If you really have a caring, animal-focused vet, he/she will care more about the treatment of the animal than your up-front payment. Like rabbitsncavyluv said, have you looked into care credit? I'm positive, that if you had a sprained or broken leg, wouldn't you appreciate some treatment and pain medication? I've broken plenty of bones, and I certainly appreciated the medical treatment I got. I would try as hard as I could to get the pig to the vet.
Now, for what you can do, you are right in the matter of home treatment. There isn't any. Seperate him from the other pig and make sure his water and food are in easy reach of him. It wouldn't hurt to use fleece or at least towels for him, to make the surface more comfortable.