Annie is correct many clinics will help set up a payment plan....you can also try for care credit...a cc to help our pets when your income is low....good luck♥
http://www.carecredit.com/
Time to take everyone to the vet. They should be treated with Revolution or Frontline, and of course checked for worms and other problems. See if you can find a vet with a payment plan, or put it on your Visa and pay a little each month, if money is the issue. But those kitties need medical help. Good luck!
oh dear this is gone beyond something you can successfully treat yourself or just leave...a flea infestation leads to tapeworms and many health problems for the cats and humans within your home....I will send you a link to read but please get these poor cats treated by a Vet...(NOT over the counter remedies...too late for that)
take them to a Vet asap....♥
http://www.pet-informed-veterinary-advice-online.com/tapeworm-life-cycle.html