Suggest Treatment For Pain In Ankle After An Injury

I twisted my ankle yesterday at 10am. It didn't hurt at the time, but about 4 hours later the right side bottom of my right foot hurt, but only when I walk. It still hurts very bad, and I can only walk on the ball of my foot, which is now causing a shin splint. After sitting for a few hours, I can take about three steps before the nauseating pain starts. What should I do? I don't have health insurance and I work in a kitchen, so have to be on my fee all day.