You really should get that looked at
A bad tooth can lead to all kinds of complications including menigitis. It's extremely important to look after ear and tooth/gum/eye infections immediately. Not only can it spread to your brain, but also your bone.
Talk to your dentist and explain about not having insurance and work out a payment plan. Or go to an ER. Everyone is entitled to proper health care, health insurance or not. There are free clinics and hospitals that tend to patients who don't have insurance.
Don't sit there in pain. You say you are on antibiotics for something, but that may not be the right antibiotic for whatever infection is going on with your tooth, and even if it is, that's not solving the problem with the tooth, just keeping the infection at bay and not doing a very good job of it considering the pain you are in.
I can't make you go and get it taken care of, but as a nurse I'm strongly advising you to do so before it turns into something worse and costs even more money.