8.4 yikes! Much too high. You’re actually in the insulin range now. My suggestion is to take your Metformin if you can tolerate it and any other glycemic meds.Ideally perhaps a victozia or ozempic to help lower your A1C. At 8.0 U I take a short acting insulin x3 daily And a long acting insulin before bedtime because I spike at nights. Jardiance helps and it protects my heart (another name for diabetes is heart disease). I check my BS 4 x daily before each meal and before bedtime. The truth is diabetes type 2 (I’m assuming that’s what you have ,check with your doctor because type 1 is a different ballgame)is curable if you watch your diet stay away from the carbohydrates fats and sugars. If you go on a keto diet and lose weight your A1c will come down immediately. But don’t forget to do your walking or some exercise every day or every other day because that also helps lower your blood sugar.Hope that helps. Remember the 3 numbers you must keep down are your Blood sugar blood pressure and cholesterol .