Suggest Treatment For Pimple On Back

have a pimple on my back, its very large it has been there for about a week . has 3 holes nothing comes out when i squeeze it. now it also has like a white ring all the way around it. my upper back is now hurting , i dont know if its because of the pimple , but its in that area. i have soaked with warm water to see if it helps it , it doesnt help,what do i do?