I have not urinated in 2 days please tell me what I need to do...

Go to an ER. As it is sunday and might be hard to get an immediate appointment with your regular doctor - go to an er. A major function of urination is to rid your body of waste - if you don't, the stuff that should not be in you remains in you. You might get an infection (UTI) and that can be hard to get rid of, so don't delay. Have this attended to. Best!