Hi Amy Jo,
It must be so frustrating to have your cat and your son sick at the same time. Although i agree you need to have it checked out, do tell the vet if there are some noticeable coincidences between your cat's symptoms and your son's. Perhaps it's something you're using to clean as an example? But again, it's important to have it checked out.
However, if you have to use your rent money, there may be some help out there for you. I can't say for sure, but I can suggest some possibilities.
Find the no-kill and rescue groups in your area (I'll give you a link to find a listing of them). Call them and explain your situation, and tell them it means using your rent money, and you have a young son, is there anything they can do to help you find either a low-cost vet, or perhaps help you in any way. They may not, but you never know unless you ask. When I took in a pregnant cat one of the local rescue groups actually paid for a vet visit so I could get the mom and kittens checked for a upper respiratory infection and for the antibiotics (I kicked in $20, which they appreciated). The vet only saw one kitten, but basically they said if one had something, they all did, and it did work out that way. Since the vet worked with this group, she gave me medicine for all.
Is it what I would have done if I had lots of money? Nope, I probably would have brought them all in, but I'm on a fixed income, and they were really great to help. And if the vet had said, based on seeing the kitten and what I said that they all needed to be seen, they would have helped with that too.
To find a list of no kill rescue groups in your area, go to www.petfinder.com
In the upper right hand area click on shelter and rescue groups, then put in your state for a local list.
I don't know if all the rescue groups would do that, but again, it can't hurt to ask. You never know what help you may find.
In fact, after that I started to foster for them, and because of the time and energy I've put in, they've helped me in other ways too, like with shots, which I got at a very discounted price.
Also, check with your local Petsmart or Petco. Some of them have vets right there, and I don't know if their prices are less than a private vet, but it can't hurt to ask and check (each area is different). Also, if you have a vet school near you, call and see if they have a low-cost clinic. The one near me doesn't, but again, you never know.
If (and I hope this is not the case, but if they do need major emergency care (like an operation) that would be prohibitively expensive, here are a list of organizations that will help pay for something like that (only emergency situations) for people with low incomes.
Click on this link, then click on the 2nd choice "Can DDAF help me pay my companion animal's medical bills?" You'll bring up a list of places you can apply to for emergency help. Below that if you scroll down are some area-specific groups also. And do check the "general/miscellaneous" in the first list, because there are more resources there too. Read through them and see if there is anything that can help you even with non-emergency situations (which I haven't read through completely so who knows, there might be).http://www.ddaf.org/faq/
I think when people who really have financial problems are trying their best to do the best for their animals despite the problems, and are willing to sacrifice if they have to, that's when I find people and places are willing, if at all possible, to help. That's why even when they helped me with the kittens, and they were going to take them to put up for adoption, I still wanted to put in something, even if it was $20, because they now could use that $20 to help someone else.
I do know how hard it can be. The vet might even be willing to let you pay some out if you give them something.
Good luck, and let us know what happens.