I have an ingrown hair grew quickly to 1/2 golf ball with chills, fever, and pain. doctor gave bactrim (sulfamethoxazole and trimethoprim) but didn't lance it. should it be lanced?

Abscess/boil: If it is truly infected and becoming an abscess or boil, they often need to be drained, be it an "auto i;d" where antibiotics and often warm compresses or even a "drawing slave" can help the area open and drain itself. If that does not work than surgical i;d may be required (lancing). On some occasions, depending on the site, it may heal without lancing. If persists, worsens, enlarges, see dr.

Yes: One unsuccessful round of antibiotics. Go back to doctor who now might decide to lance and drain and pack wound in addition to another round of antibiotics.