I have an infection in my tooth

I have an infection in or under my tooth I don’t know. It doesn’t hurt yet or really should say it only hurts when I brush my teeth. The gums around the tooth are inflamed and it feels like a cut. I know it’s not though. I know it’s infected and it will hurt, badly very soon if I don’t get it taken care of.

I have no health insurance. I’m low on money and I have no idea what to do.

Edit: i know it’s the tooth and not just the gums because there’s a huge cavity on the bottom of the tooth.