Help me save a stray

This started because yesterday 23/11/2021 I saw a stray kitten crying its heart out, while hiding in the trash.

It's about 3 weeks old.

I decided on impulse to pick it up and bring it back home, even though I live in a very crumped space with my family and my dog.

It was INFESTED with fleas and even blood came out from it's fur when I bathed it(it was an emergency situation, otherwise I wouldn't have bathed it while its so young) and I was afraid it would die from blood loss/parasites.

I took it to the vet and I was told that it barely survived death.Even though it's still a baby and can't even get it's vaccines yet, the vet told me that I need to give it special medication and and diet in order for it to survive. It has respiratory issues and a virus that attacks the heart, lungs and eyes. Contagious as well.

I'm only 18 years old in a family of 6 and I have no means to pay for its medical bills.

PAny help is appreciated. Thank you for reading this long.