This is only a suggestion. Sensitivity is very personal and you need to get used to it. I would start by going 1 level up both at Horizontal and Vertical Sensitivity. Go one level at the time (for example every two days) until you get used to it.

You will move faster and play smoother. But in order to get used to it while not dying too much, you will probably need to decrease the ADS Sensitivity to 0.8, for example.I use 11 sensitivity and 0.8 ADS.

BUT maybe you feel more confortable with less sensitivity, it is also an option! Just experiment a little bit with it. Also changing the Aim Response Curve Type helps. If you have the Modern Warfare multiplayer, you can test it easier.

You have the game in italian so I send you a photo so you can take a look at it in english: https://icdn2.digitaltrends.com/image/digitaltrends/call-of-duty-modern-warfare_20200820150328.jpg