I’ve had sinus infections and found that I usually had to double basal rates (in some pumps that means +100%, in others 200%, same doubling, but confusing number semantics!) yet still had poorer control.
I know at the time I was very worried that the antibiotics would kick in and my blood glucose would drop off the cliff into dangerous hypoglycemia. That never happened to me. The basal need reduction backed off in a relatively slow manner. Try to return, as best you can, to your former basal rates, but be patient.
Infections just wreak havoc with blood sugar; I’ve never managed them well. The best course is to take your antibiotics and do whatever it takes to get well. Good luck.