Hi, My Mom Is A Type 2 Diabetic And Not

Hi, my mom is a type 2 diabetic and not feeling well the last few days. Cold, sinus, fatigue symptoms. She is fully vaccinated for covid for last month. I got her Coricidin which helped the symptoms. However, we have seen a huge increase in her sugar levels. Ranging from 160-270. She normally can control and keep in safe range of 100.
Which that said she feels worse. Could the coricidin caused this? What other over the counter medicine is best for her having high blood pressure and diabetes?
I’m just at a loss of how to improve her.