I’ve had a similar situation before where antibiotics didn’t really help, and the pain just kept getting worse. In my case, even though I had old root canals, it turned out there was a hidden crack and a deep infection under one of my crowns that standard x-rays missed. I only found out when I insisted on more advanced imaging at my dentist’s office. The combination of facial pain, congestion, and worsening tooth pain sounds like it could be more than just a regular infection or sinus issue, so I’d say try to get in with a dentist or endodontist who can do a thorough check, maybe with 3D imaging or CBCT if possible.