You might want to talk to your doctor about that. An untreated tooth is like adding poison to your body. I knew a guy that let his teeth go and never when to a dentist and now he has to take a pill everyday for the rest of his life. It takes a while before that happens but it can.
I would be wary of what hospital to go to an infection can cause those symptoms but not very often I would go back to your dentists and see what they have to say hope you feel better soon x