Oh no! Big hugs to you. I know how scary this can be.
There's really not much you can do besides take him to the vet if the dog is still vomiting/diarrhea/no appetite. I would go ahead and just take him to the vet - explain to him your financial situation - I'm sure he'll understand as he got your money the last time - and see if he can put you on a payment plan for whatever cost the vet visit comes out to be. He'll probably order an x-ray and then it might not be too bad.
Hope everything turns out okay!