Hello . Early Last Week I Was Brushing My Teeth

Hello . early last week I was brushing my teeth and my gums started to itch badly so I used my tooth brush to scratch my gums and sense then I have a horrible looking wound that will not go away no matter what I do . and now I can barely eat or drink anything . should I go to an E.R or the dentist ? . I been worrying if I go to an E.R they will not do anything .