Help Me Help Riley

Riley took a fall down the stairs on Wednesday January 18. He seemed fine, just a limp. Since then he's gotten progressively worse. He is vomiting, not eating, unable to walk and is forcing air out of his mouth. We took him to the vet on Friday to get xrays and they couldn't find anything other than a little arthritis and backed up feces in his intestines. He had a bm on Saturday, nothING since. He ate a little poached chicken, about 1/4 cup but refused rice and chicken broth. He drinks water, but vomits within 5 minutes of drinking. No one is willing to work out a payment plan and I have contacted a dozen vets in and around my area. We are in modification on our mortgage are and if we miss a payment we will be in default. The money we have has got to go for our mortgage and there is no extra for a vet. My parents were kind and generous enough to pay for the xrays meds and diagnostics. I can't stand to see my dog suffering because we can't afford to help him. I'm in a Golden Retriever group and some members have suggested I set this up so that's what I'm doing. I appreciate it so much if you are able to help but if you're not and can help my sending us your prayers, good wishes and thoughts I'll take those too! Thank you in advance.