Having pain in node a week ago and it's enlarged. went to doctor and got antibiotic, no other symptoms, now brown spots on throat, worried.

Diagnosis: You noted an enlarged painful lymph node. Your doctor gave you antibiotics. You now have brown spots in your throat. Your doctor gave you a diagnosis. You should ask what that was and write it down. For a painful enlarged lympn node your doctor is concerned about a bacterial infection. Maybe from an injury or a bite? If the lymph node pain goes away that is good. Follow up is important