I have a scrotum mass that was painful esp on my groin (left side) and puss has been coming out for a week. The pain is gone but the mass is there?

See Doctor. Sounds like a scrotal abscess. You need to make sure it's drained and may need help along with antibiotics.
See a doctor! Mass could be infection or tumor; pus oozing out is a concerning sign! you didn't tell much about yourself - age? Other health conditions? Unprotected sex? Many infections and other problems may partly improve on their own, but not fully go away - you should definitely see your primary care doctor, an urgent care or std clinic to get this checked out and treated right away!