Can anyone give me a suggestion?

My dog got both heartworm and ticks fever at the same time and now
being taken medicine .He get thinner and thiner as he not willing to
eat any food although I gave him meat and chicken.He got thiner and
thiner and I dont think he cant affort more than 1 weeks. So what can
I do with him? I know it can take him to vet clinic for fluid
therapy.But I am almost use up all the saving money to treat the
disaseas! So anyone can help me ?
.