Meds for abandoned black kitten

I took a black kitten that was abandoned in the street and about 1.5 month old, he has a huge sore eating his nose and now reaching the eye, I am providing foster home but this expense was not expected and I cannot afford it at this moment. Please help me, I know he is in pain and I couldn’t turn my back on him, I will provide receipts and vet info if you want to check about his treatment. I need to cover Vaccines, Deworming, Fleas, and the medical costs to treat this thing in his face.