Please save coffie he needs ur help

I have been kindly been lent 1200 to start his medication after getting over an infection coffie has a shinny coat but is very thin and pale gum . Its pretty clear without the medication he will pass away within 5 weeks I'm guessing the vet gave him 4-8 weeks on 15th of September. Coffie is eating aswell so his prognosis is good if he gets a full course of medication cost is in 2 amounts . 1st cost $1200 2nd cost $2800 something i haven't look at it too much as all I saw was the 27... that's not including vets visits bloods etc . So anything people can help with will guarantee he receives the full 82 day treatment.