Horrible headaches..post vitrectomy sceral buckle

I am 15 days post surgery and have been absolutely miserable through this whole process. Have completed 6 days face down now in recliner, head down for most of the time. Still have gas bubble so all is a big blur. I am experiencing severe headaches to the point of nausea. Dr says all looks good but some inflamation so put me on 7 days of prednisone. It helped first day or two now headaches have returned and do not go away. Taking 1500mg Tylenol every 3 hrs to manage pain. Has anyone else had this happen? When will it improve?