Sinus pain/pressure, no pus per ent doctor. 2 rounds of antibiotics zpac and augmentin (amoxicillin and clavulanate). had a shot of cortisone on thursday. any advice?

Need more testing: If steroids and 2 antibiotic course dont touch your symptoms, you may need imaging like a ct scan or endoscopy to better assess the cause. This may not be sinus related or may be an atypical headache..see someone if there is no improvement

Promote drainage: You want to give the medicine a chance to work. I would try things to promote drainage, such as mucinex, (guaifenesin) nasal decongestants similar to Afrin like sprays for a short time 3-4 days, nasal saline may also help.