Suggest Remedy For Swelling And Numbness On Wrists

Hey. Idk what to do. I had an accident in june n cut my wrist and severed my tendon's. Went to er n they just sewed outside up n told me I don't need surgery. Now my wrist is swollen and knumb and no feeling around the scar n pinky finger down, I feel nerves. Do I need surgery or is it to late?